ESHRE PGD Consortium data collection XIV-XV: cycles from January 2011 to December 2012 with pregnancy follow-up to October 2013

Preimplantation genetic testing in the current era, a review

BACKGROUND

Preimplantation genetic testing (PGT), also referred to as preimplantation genetic diagnosis (PGD), is an advanced reproductive technology used during in vitro fertilization (IVF) cycles to identify genetic abnormalities in embryos prior to their implantation. PGT is used to screen embryos for chromosomal abnormalities, monogenic disorders, and structural rearrangements.

DEVELOPMENT OF PGT

Over the past few decades, PGT has undergone tremendous development, resulting in three primary forms: PGT-A, PGT-M, and PGT-SR. PGT-A is utilized for screening embryos for aneuploidies, PGT-M is used to detect disorders caused by a single gene, and PGT-SR is used to detect chromosomal abnormalities caused by structural rearrangements in the genome.

PURPOSE OF REVIEW

In this review, we thoroughly summarized and reviewed PGT and discussed its pros and cons down to the minutest aspects. Additionally, recent studies that highlight the advancements of PGT in the current era, including their future perspectives, were reviewed.

CONCLUSIONS

This comprehensive review aims to provide new insights into the understanding of techniques used in PGT, thereby contributing to the field of reproductive genetics.

Preimplantation genetic testing for monogenic disorders (PGT-M) offers an alternative strategy to prevent children from being born with hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes: a retrospective study

BACKGROUND

Preimplantation genetic testing for monogenic disorders (PGT-M) is now widely used as an effective strategy to prevent various monogenic or chromosomal diseases.

MATERIAL AND METHODS

In this retrospective study, couples with a family history of hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes and/or carrying the pathogenic genes underwent PGT-M to prevent children from inheriting disease-causing gene mutations from their parents and developing known genetic diseases. After PGT-M, unaffected (i.e., normal) embryos after genetic detection were transferred into the uterus of their corresponding mothers.

RESULTS

A total of 43 carrier couples with the following hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes underwent PGT-M: Duchenne muscular dystrophy (13 families); methylmalonic acidemia (7 families); spinal muscular atrophy (5 families); infantile neuroaxonal dystrophy and intellectual developmental disorder (3 families each); Cockayne syndrome (2 families); Menkes disease, spinocerebellar ataxia, glycine encephalopathy with epilepsy, Charcot-Marie-Tooth disease, mucopolysaccharidosis, Aicardi-Goutieres syndrome, adrenoleukodystrophy, phenylketonuria, amyotrophic lateral sclerosis, and Dravet syndrome (1 family each). After 53 PGT-M cycles, the final transferable embryo rate was 12.45%, the clinical pregnancy rate was 74.19%, and the live birth rate was 89.47%; a total of 18 unaffected (i.e., healthy) children were born to these families.

CONCLUSIONS

This study highlights the importance of PGT-M in preventing children born with hereditary neurological diseases or metabolic diseases dominated by nervous system phenotypes.

How should the best human embryo in vitro be? Current and future challenges for embryo selection

In-vitro fertilization (IVF) aims at overcoming the causes of infertility and lead to a healthy live birth. To maximize IVF efficiency, it is critical to identify and transfer the most competent embryo within a cohort produced by a couple during a cycle. Conventional static embryo morphological assessment involves sequential observations under a light microscope at specific timepoints. The introduction of time-lapse technology enhanced morphological evaluation via the continuous monitoring of embryo preimplantation in vitro development, thereby unveiling features otherwise undetectable via multiple static assessments. Although an association exists, blastocyst morphology poorly predicts chromosomal competence. In fact, the only reliable approach currently available to diagnose the embryonic karyotype is trophectoderm biopsy and comprehensive chromosome testing to assess non-mosaic aneuploidies, namely preimplantation genetic testing for aneuploidies (PGT-A). Lately, the focus is shifting towards the fine-tuning of non-invasive technologies, such as "omic" analyses of waste products of IVF (e.g., spent culture media) and/or artificial intelligence-powered morphologic/morphodynamic evaluations. This review summarizes the main tools currently available to assess (or predict) embryo developmental, chromosomal, and reproductive competence, their strengths, the limitations, and the most probable future challenges.

Preimplantation genetic testing for embryos predisposed to hereditary cancer: Possibilities and challenges

Preimplantation genetic testing (PGT), which was developed as an alternative to prenatal genetic testing, allows couples to avoid pregnancies with abnormal chromosomes and the subsequent termination of the affected fetus. Originally used for early onset monogenic conditions, PGT is now used to prevent various types of inherited cancer conditions based on the development of PGT technology, assisted reproductive techniques (ARTs), and in vitro fertilization (IVF). This review provides insights into the potential benefits and challenges associated with the application of PGT for hereditary cancer and provides an overview of the existing literature on this test, with a particular focus on the current challenges related to laws, ethics, counseling, and technology. Additionally, this review predicts the future potential applications of this method. Although PGT may be utilized to predict and prevent hereditary cancer, each case should be comprehensively evaluated. The motives of couples must be assessed to prevent the misuse of this technique for eugenic purposes, and non-pathogenic phenotypes must be carefully evaluated. Pathological cases that require this technology should also be carefully considered based on legal and ethical reasoning. PGT may be the preferred treatment for hereditary cancer cases; however, such cases require careful case-by-case evaluations. Therefore, this study concludes that multidisciplinary counseling and support for patients and their families are essential to ensure that PGT is a viable option that meets all legal and ethical concerns.

Investigation of the risk of paternal cell contamination in PGT and the necessity of intracytoplasmic sperm injection

ICSI is widely recommended for patients undergoing preimplantation genetic testing (PGT), but are sperm a potential source of paternal cell contamination in PGT? Semen samples were obtained from five normozoospermic men consenting to research. From each sample 1, 2, 4, 8 and 10 sperm were collected in PCR tubes and whole genome amplification according to PGT-A and PGT-SR processing protocols was undertaken. None of the 25 samples submitted (a total of 125 sperm) showed evidence of DNA amplification. Thus, paternal cell contamination resulting from using conventional in vitro fertilization (IVF) as the insemination method, carries a low risk of an adverse event or misdiagnosis in PGT-A. Due to the higher risk incurred with PGT-SR, clinics may wish to exercise increased caution and continue using ICSI, while PGT-M involves different processing protocols, presenting a different risk profile.

Preimplantation genetic testing for Neurofibromatosis type 1: more than 20 years of clinical experience

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder that affects the skin and the nervous system. The condition is completely penetrant with extreme clinical variability, resulting in unpredictable manifestations in affected offspring, complicating reproductive decision-making. One of the reproductive options to prevent the birth of affected offspring is preimplantation genetic testing (PGT). We performed a retrospective review of the medical files of all couples (n = 140) referred to the Dutch PGT expert center with the indication NF1 between January 1997 and January 2020. Of the couples considering PGT, 43 opted out and 15 were not eligible because of failure to identify the underlying genetic defect or unmet criteria for in vitro fertilization (IVF) treatment. The remaining 82 couples proceeded with PGT. Fertility assessment prior to IVF treatment showed a higher percentage of male infertility in males affected with NF1 compared to the partners of affected females. Cardiac evaluations in women with NF1 showed no contraindications for IVF treatment or pregnancy. For 67 couples, 143 PGT cycles were performed. Complications of IVF treatment were not more prevalent in affected females compared to partners of affected males. The transfer of 174 (out of 295) unaffected embryos led to 42 ongoing pregnancies with a pregnancy rate of 24.1% per embryo transfer. There are no documented cases of misdiagnosis following PGT in this cohort. With these results, we aim to provide an overview of PGT for NF1 with regard to success rate and safety, to optimize reproductive counseling and PGT treatment for NF1 patients.

Preclinical workup using long-read amplicon sequencing provides families with de novo pathogenic variants access to universal preimplantation genetic testing

STUDY QUESTION

Can long-read amplicon sequencing be beneficial for preclinical preimplantation genetic testing (PGT) workup in couples with a de novo pathogenic variant in one of the prospective parents?

SUMMARY ANSWER

Long-read amplicon sequencing represents a simple, rapid and cost-effective preclinical PGT workup strategy that provides couples with de novo pathogenic variants access to universal genome-wide haplotyping-based PGT programs.

WHAT IS KNOWN ALREADY

Universal PGT combines genome-wide haplotyping and copy number profiling to select embryos devoid of both familial pathogenic variants and aneuploidies. However, it cannot be directly applied in couples with a de novo pathogenic variant in one of the partners due to the absence of affected family members required for phasing the disease-associated haplotype.

STUDY DESIGN, SIZE, DURATION

This is a prospective study, which includes 32 families that were enrolled in the universal PGT program at the University Hospital of Leuven between 2018 and 2022. We implemented long-read amplicon sequencing during the preclinical PGT workup to deduce the parental origin of the disease-associated allele in the affected partner, which can then be traced in embryos during clinical universal PGT cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

To identify the parental origin of the disease-associated allele, genomic DNA from the carrier of the de novo pathogenic variant and his/her parent(s) was used for preclinical PGT workup. Primers flanking the de novo variant upstream and downstream were designed for each family. Following long-range PCR, amplicons that ranged 5-10 kb in size, were sequenced using Pacific Bioscience and/or Oxford Nanopore platforms. Next, targeted variant calling and haplotyping were performed to identify parental informative single-nucleotide variants (iSNVs) linked to the de novo mutation. Following the preclinical PGT workup, universal PGT via genome-wide haplotyping was performed for couples who proceeded with clinical PGT cycle. In parallel, 13 trophectoderm (TE) biopsies from three families that were analyzed by universal PGT, were also used for long-read amplicon sequencing to explore this approach for embryo direct mutation detection coupled with targeted long-read haplotyping.

MAIN RESULTS AND THE ROLE OF CHANCE

The parental origin of the mutant allele was identified in 24/32 affected individuals during the preclinical PGT workup stage, resulting in a 75% success rate. On average, 5.95 iSNVs (SD = 4.5) were detected per locus of interest, and the average distance of closest iSNV to the de novo variant was ∼1750 bp. In 75% of those cases (18/24), the de novo mutation occurred on the paternal allele. In the remaining eight families, the risk haplotype could not be established due to the absence of iSNVs linked to the mutation or inability to successfully target the region of interest. During the time of the study, 12/24 successfully analyzed couples entered the universal PGT program, and three disease-free children have been born. In parallel to universal PGT analysis, long-read amplicon sequencing of 13 TE biopsies was also performed, confirming the segregation of parental alleles in the embryo and the results of the universal PGT.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this approach is that it remains targeted with the need to design locus-specific primers. Because of the restricted size of target amplicons, the region of interest may also remain non-informative in the absence of iSNVs.

WIDER IMPLICATIONS OF THE FINDINGS

Targeted haplotyping via long-read amplicon sequencing, particularly using Oxford Nanopore Technologies, provides a valuable alternative for couples with de novo pathogenic variants that allows access to universal PGT. Moreover, the same approach can be used for direct mutation analysis in embryos, as a second line confirmation of the preclinical PGT result or as a potential alternative PGT procedure in couples, where additional family members are not available.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by KU Leuven funding (no. C1/018 to J.R.V.) and Fonds Wetenschappelijk Onderzoek (1241121N to O.T.). J.R.V. is co-inventor of a patent ZL910050-PCT/EP2011/060211-WO/2011/157846 'Methods for haplotyping single-cells' and ZL913096-PCT/EP2014/068315-WO/2015/028576 'Haplotyping and copy number typing using polymorphic variant allelic frequencies' licensed to Agilent Technologies. All other authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Preimplantation genetic testing and child health: a national register-based study

STUDY QUESTION

Is preimplantation genetic testing (PGT) associated with adverse perinatal outcome and early childhood health?

SUMMARY ANSWER

Children born after PGT had comparable perinatal outcomes to children born after IVF/ICSI and comparable findings regarding early childhood health.

WHAT IS KNOWN ALREADY

PGT is offered to couples affected by monogenic disorders (PGT-M) or inherited chromosomal aberrations (PGT-SR), limiting the risk of transferring the disorder to the offspring. PGT, an invasive technique, requires genetic analysis of one or up to ten cells from the embryo and is combined with IVF or ICSI. Several studies, most of them small, have shown comparable results after PGT and IVF/ICSI concerning perinatal outcome. Only a few studies with limited samples have been published on PGT and childhood health.

STUDY DESIGN, SIZE, DURATION

We performed a register-based study including all singletons born after PGT (n = 390) in Sweden during 1 January 1996-30 September 2019. Singletons born after PGT were compared with all singletons born after IVF/ICSI (n = 61 060) born during the same period of time and with a matched sample of singletons (n = 42 034) born after spontaneous conception selected from the Medical Birth Register. Perinatal outcomes, early childhood health, and maternal outcomes were compared between pregnancies after PGT and IVF/ICSI as well as between pregnancies after PGT and spontaneous conception. Primary outcomes were preterm birth (PTB) and low birthweight (LBW) whereas childhood morbidity was the secondary outcome.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on women who went through PGT and gave birth were obtained from the local databases at the two PGT centres in Sweden, whereas data on IVF treatment for the IVF/ICSI group were obtained from the national IVF registers. These data were then cross-linked to national health registers; the Medical Birth Register, the Patient Register, and the Cause of Death Register. Logistic multivariable regression analysis and Cox proportional hazards models were performed with adjustment for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean follow-up time was 4.6 years for children born after PGT and 5.1 years for children born after spontaneous conception, whereas the mean follow-up time was 9.0 years for children born after IVF/ICSI. For perinatal outcomes, PTB occurred in 7.7% of children after PGT and in 7.3% of children after IVF/ICSI, whereas the rates were 4.9% and 5.2% for LBW (adjusted odds ratio (AOR) 1.22, 95% CI 0.82-1.81 and AOR 1.17, 95% CI 0.71-1.91, respectively). No differences were observed for birth defects. In comparison to spontaneous conception, children born after PGT had a higher risk for PTB (AOR 1.73, 95% CI 1.17-2.58). Regarding early childhood health, the absolute risk of asthma was 38/390 (9.7%) in children born after PGT and 6980/61 060 (11.4%) in children born after in IVF/ICSI, whereas the corresponding numbers were 34/390 (8.7%) and 7505/61 060 (12.3%) for allergic disorders. Following Cox proportional hazards models, no significant differences were found for these outcomes. Sepsis, hypothyroidism, attention deficit hyperactivity disorder, autism spectrum disorders, mental retardation, cerebral palsy, and epilepsy were diagnosed in a maximum of three PGT children. No PGT children died during the follow-up period. Regarding maternal outcomes, the rates of placenta praevia and caesarean delivery were significantly higher after PGT in comparison to spontaneous conception (AOR 6.46, 95% CI 3.38-12.37 and AOR 1.52, 95% CI 1.20-1.92, respectively), whereas no differences were seen comparing pregnancies after PGT and IVF/ICSI.

LIMITATIONS, REASONS FOR CAUTION

The rather small sample size of children born after PGT made it impossible to adjust for all relevant confounders including fertilization method and culture duration. Moreover, the follow-up time was short for most of the children especially in the PGT group, probably lowering the absolute number of diagnoses in early childhood.

WIDER IMPLICATIONS OF THE FINDINGS

The results are reassuring and indicate that the embryo biopsy itself has no adverse effect on the perinatal, early childhood, or maternal outcomes. Although the results are comparable to IVF/ICSI also regarding early childhood outcome, they should be taken with caution due to the low number of children with diagnoses and short follow-up time. Long-term follow-up studies on children born after PGT are scarce and should be conducted considering the invasiveness of the technique.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), the Board of National Specialised Medical Care at Sahlgrenska University Hospital and Hjalmar Svensson Research Foundation. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

ESHRE PGT Consortium data collection XXI: PGT analyses in 2018

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN SIZE DURATION

The data for PGT analyses performed between 1 January 2018 and 31 December 2018 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform, which is based on genetic analysis and has been in use since 2016.

PARTICIPANTS/MATERIALS SETTING METHODS

Data on biopsy method, diagnostic technology, and clinical outcome were submitted by 44 centres. Records with analyses for more than one PGT for monogenic disorders (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR), or with inconsistent data regarding the PGT modality, were excluded. All transfers performed within 2 years after the analysis were included, enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2018 covers a total of 1388 analyses for PGT-M, 462 analyses for PGT-SR, 3003 analyses for PGT for aneuploidies (PGT-A), and 338 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 19% in 2016-2017 to 33% in 2018), is status quo for PGT-SR (from 30% in 2016-2017 to 33% in 2018) and has become the most used biopsy stage for PGT-A (from 87% in 2016-2017 to 98% in 2018) and for concurrent PGT-M/SR with PGT-A (96%). The use of comprehensive, whole-genome amplification (WGA)-based diagnostic technology showed a small decrease for PGT-M (from 15% in 2016-2017 to 12% in 2018) and for PGT-SR (from 50% in 2016-2017 to 44% in 2018). Comprehensive testing was, however, the main technology for PGT-A (from 93% in 2016-2017 to 98% in 2018). WGA-based testing was also widely used for concurrent PGT-M/SR with PGT-A, as a standalone technique (74%) or in combination with PCR or FISH (24%). Trophectoderm biopsy and comprehensive testing strategies are linked with higher diagnostic efficiencies and improved clinical outcomes per embryo transfer.

LIMITATIONS REASONS FOR CAUTION

The findings apply to the data submitted by 44 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

The Consortium datasets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTERESTS

The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Day 5 versus day 3 embryo biopsy for preimplantation genetic testing for monogenic/single gene defects

BACKGROUND

Assisted reproductive technology (ART) has allowed couples with a family history of a monogenic genetic disease, or a disease-carrying gene, to reduce the chance of them having a child with the genetic disorder. This is achieved by genetically testing the embryos using an advanced process called preimplantation genetic testing for monogenic or single gene disorders (PGT-M), such as Huntington's disease or cystic fibrosis. This current terminology (PGT-M) has replaced the formerly-known preimplantation genetic diagnosis (PGD). During PGT-M, one or more embryo cells are biopsied and analysed for genetic or chromosomal anomalies before transferring the embryos to the endometrial cavity. Biopsy for PGT-M can be performed at day 3 of cleavage-stage embryo development when the embryo is at the six- to the eight-cell stage, with either one or two blastomeres being removed for analysis. Biopsy for PGT-M can also be performed on day 5 of the blastocyst stage of embryo development when the embryo has 80 to 100 cells, with five to six cells being removed for analysis. Day 5 biopsy has taken over from day 3 biopsy as the most widely-used biopsy technique; however, there is a lack of summarised evidence from randomised controlled trials (RCTs) that assesses the effectiveness and safety of day 5 biopsy compared to day 3 biopsy. Since biopsy is an invasive process, whether it is carried out at day 3 or day 5 of embryo development may have different impacts on further development, implantation, pregnancy, live birth and perinatal outcomes.

OBJECTIVES

To assess the benefits and harms of day 5 embryo biopsy, in comparison to day 3 biopsy, in PGT-M in women undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles.

SEARCH METHODS

We searched the following electronic bibliographic databases in December 2021 to identify relevant RCTs: the Cochrane Gynaecology and Fertility Group (CGFG) Specialised Trials Register; CENTRAL, MEDLINE, Embase and PsycINFO. We also handsearched grey literature, such as trial registers, relevant journals, reference lists, Google Scholar, and published conference abstracts.

SELECTION CRITERIA

Eligible RCTs compared day 5 versus day 3 embryo biopsy for PGT-M.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live births and miscarriages. We calculated outcomes per woman/couple randomised and reported odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

We included one RCT involving 20 women. The evidence was of very low certainty; the main limitations of the study were serious risk of bias due to lack of blinding of study personnel, and imprecision. We are uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on live births (OR 1.50, 95% CI 0.26 to 8.82; 1 RCT, 20 women; very low-certainty evidence). The evidence suggests that if the chance of live birth following day 3 biopsy was assumed to be 40%, then the chance with day 5 biopsy is between 15% and 85%. It is also uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on miscarriages (OR 1.00, 95% CI 0.05 to 18.57; 1 RCT, 20 women; very low-certainty evidence).  We are uncertain whether day 5 embryo biopsy compared to day 3 biopsy has an effect on other secondary outcome measures, including viable intrauterine pregnancies (OR 2.25, 95% CI 0.38 to 13.47; 1 RCT, 20 women; very low-certainty evidence), ectopic pregnancies (OR 0.16, 95% CI 0.01 to 3.85; 1 RCT, 20 women; very low-certainty evidence), stillbirths (OR not estimable as no events in either group; 1 RCT, 20 women; very low-certainty evidence) or termination of pregnancies (OR 3.32, 95% CI 0.12 to 91.60; 1 RCT, 20 women; very low-certainty evidence). No studies reported on gestational age at birth, birthweight, neonatal mortality and major congenital anomaly.

AUTHORS' CONCLUSIONS

We are uncertain if there is a difference in live births and miscarriages, viable intrauterine pregnancies, ectopic pregnancies, stillbirths or termination of pregnancies between day 5 and day 3 embryo biopsy for PGT-M. There was insufficient evidence to draw any conclusions regarding other adverse outcomes. The results should be interpreted with caution, as the evidence was of very low certainty due to limited studies, high risk of bias in the included study, and an overall low level of precision.

Simultaneous detection of genomic imbalance in patients receiving preimplantation genetic testing for monogenic diseases (PGT-M)

Background: Preimplantation genetic test for monogenic disorders (PGT-M) has been used to select genetic disease-free embryos for implantation during in vitro fertilization (IVF) treatment. However, embryos tested by PGT-M have risks of harboring chromosomal aneuploidy. Hence, a universal method to detect monogenic diseases and genomic imbalances is required.

Methods: Here, we report a novel PGT-A/M procedure allowing simultaneous detection of monogenic diseases and genomic imbalances in one experiment. Library was prepared in a special way that multiplex polymerase chain reaction (PCR) was integrated into the process of whole genome amplification. The resulting library was used for one-step low-pass whole genome sequencing (WGS) and high-depth target enrichment sequencing (TES).

Results: The TAGs-seq PGT-A/M was first validated with genomic DNA (gDNA) and the multiple displacement amplification (MDA) products of a cell line. Over 90% of sequencing reads covered the whole-genome region with around 0.3–0.4 × depth, while around 5.4%–7.3% of reads covered target genes with >10000 × depth. Then, for clinical validation, 54 embryos from 8 women receiving PGT-M of β-thalassemia were tested by the TAGs-seq PGT-A/M. In each embryo, an average of 20.0 million reads with 0.3 × depth of the whole-genome region was analyzed for genomic imbalance, while an average of 0.9 million reads with 11260.0 × depth of the target gene HBB were analyzed for β-thalassemia. Eventually, 18 embryos were identified with genomic imbalance with 81.1% consistency to karyomapping results. 10 embryos contained β-thalassemia with 100% consistency to conventional PGT-M method.

Conclusion: TAGs-seq PGT-A/M simultaneously detected genomic imbalance and monogenic disease in embryos without dramatic increase of sequencing data output.

Extracellular cell-free RNA profile in human large follicles and small follicles

Background: Previous studies have shown that a large number of valuable and functional cell-free RNAs (cfRNAs) were found in follicular fluid. However, the species and characteristics of follicular fluid cfRNAs have not been reported. Furthermore, their implications are still barely understood in the evaluation of follicular fluid from follicles of different sizes, which warrants further studies.

Objective: This study investigated the landscape and characteristics of follicular fluid cfRNAs, the source of organization, and the potential for distinguishing between follicles of different sizes.

Methods: Twenty-four follicular fluid samples were collected from 20 patients who received in vitro fertilization (n = 9) or ICSI (n = 11), including 16 large follicular fluid and 8 small follicular fluid samples. Also, the cfRNA profile of follicular fluid samples was analyzed by RNA sequencing.

Results: This result indicated that the concentration of follicular fluid cfRNAs ranged from 0.78 to 8.76 ng/ml, and fragment length was 20–200 nucleotides. The concentration and fragment length of large follicular fluid and small follicular fluid samples were not significantly different (p > 0.05). The technical replica correlation of follicular fluid samples ranged from 0.3 to 0.9, and the correlation of small follicular fluid samples was remarkably (p < 0.001) lower than that of large follicular fluid samples. Moreover, this study found that cfRNAs of the follicular fluid could be divided into 37 Ensembl RNA biotypes, and a large number of mRNAs, circRNAs, and lncRNAs were observed in the follicular fluid. The number of cfRNAs in large follicular fluid was remarkably (p < 0.05) higher than that of small follicular fluid. Furthermore, the follicular fluid contained a large amount of intact mRNA and splice junctions and a large number of tissue-derived RNAs, which are at a balanced state of supply and elimination in the follicular fluid. KEGG pathway analysis showed that differentially expressed cfRNAs were enriched in several pathways, including thyroid hormone synthesis, the cGMP-PKG signaling pathway, and inflammatory mediator regulation of TRP channels. In addition, we further showed that four cfRNAs (TK2, AHDC1, PHF21A, and TTYH1) serve as a potential indicator to distinguish the follicles of different sizes. The ROC curve shows great potential to predict follicular fluid from follicles of different sizes [area under the curve (AUC) > 0.88].

Conclusion: Overall, our study revealed that a large number of cfRNAs could be detected in follicular fluid and could serve as a potential non-invasive biomarker in distinguishing between follicles of different sizes. These results may inform the study of the utility and implementation of cfRNAs in clinical practice.

Regional and developmental characteristics of human embryo mosaicism revealed by single cell sequencing

Chromosomal mosaicism is common throughout human pre- and post-implantation development. However, the incidence and characteristics of mosaicism in human blastocyst remain unclear. Concerns and confusions still exist regarding the interpretation of chromosomal mosaicism on preimplantation genetic testing for aneuploidy (PGT-A) results and embryo development. Here, we aimed to estimate the genetic concordance between trophectoderm (TE), inner cell mass (ICM) and the corresponding human embryonic stem cells (hESCs), and to explore the characteristics of mosaicism in human blastocyst and hESCs on a single cell level. The single cell sequencing results of TE cells indicated that 65.71% of the blastocysts were mosaic (23 in 35 embryos), while the ICM sequencing results suggested that 60.00% of the blastocysts were mosaic (9 in 15 embryos). The incidence of mosaicism for the corresponding hESCs was 33.33% (2 in 6 embryos). No significant difference was observed between the mosaic rate of TE and that of ICM. However, the mosaic rate of the corresponding hESCs was significantly lower than that of TE and ICM cells, suggesting that the incidence of mosaicism may decline during embryonic development. Upon single cell sequencing, we found several “complementary” copy number variations (CNVs) that were usually not revealed in clinical PGT-A which used multi-cell DNA sequencing (or array analysis). This indicates the potential diagnostic risk of PGT-A based multi-cell analysis routinely in clinical practice. This study provided new insights into the characteristics, and considerable influences, of mosaicism on human embryo development, as well as the clinical risks of PGT-A based on multi-cell biopsies and bulk DNA assays.

Chromosomal mosaicism is a common biological phenomenon during human embryo development, which may have interferences with clinical PGT-A decision-making. In this study, single cell DNA sequencing and copy number variation (CNV) analysis were performed to estimate the genetic concordance of TE, ICM, and hESCs. The single cell sequencing results of TE cells indicated that 65.71% of the blastocysts were mosaic, while the ICM sequencing result suggested that 60.00% of the blastocysts were mosaic in the 39 embryos we analyzed. The mosaicism may be caused by both whole and segmental abnormalities of the chromosome. Our study described the characteristics of chromosome mosaicism on single cell level in human embryo and brought evidence that mosaicism could raise challenges in the clinical management of PGT-A.

Genetic of preimplantation diagnosis of dysmorphic facial features and intellectual developmental disorder (CHDFIDD) without congenital heart defects

Background

Cyclin‐dependent kinase 13 plays a critical role in the regulation of gene transcription. Recent evidence suggests that heterozygous variants in CDK13 are associated with a syndromic form of mental deficiency and developmental delay, which is inherited in an autosomal dominant manner.

Methods

A mentally retarded mother (33‐year‐old) and son (10‐year‐old boy) in our hospital with CDK13 variant (c.2149 (exon 4) G>A. p.Gly717Arg) were detected by whole‐exome sequencing (WES). All published CDK13 variant syndrome cases as of November 11, 2021, were searched, and their clinical information was recorded and summarized.

Results

We studied two patients in a Chinese family with a heterozygous constitutional CDK13 variant (c.2149 (exon 4) G>A. p.Gly717Arg), exhibiting the classical characteristics of dysmorphic facial features and intellectual developmental disorder (CHDFIDD, OMIM # 617360), without congenital heart defects. This is the first reported case of an adult patient with a CDK13 variant that gave birth to the next generation with the same variant. Preimplantation genetic testing for monogenic disease (PGT‐M) was performed for the proband and her husband with full informed consent and successfully blocked the inheritance of the disease.

Conclusion

Our study is of great significance for molecular diagnosis and genetic counseling of patients with CDHFIDD and extends the variant spectrum of CDK13.

Patients' choices and opinions on chorionic villous sampling and non-invasive alternatives for prenatal testing following preimplantation genetic testing for hereditary disorders: A cross-sectional questionnaire study

OBJECTIVE

The aim of this study was to investigate choices of and reasoning behind chorionic villous sampling and opinions on non-invasive prenatal testing among women and men achieving pregnancy following preimplantation genetic testing (PGT) for hereditary disorders.

METHODS

A questionnaire was electronically submitted to patients who had achieved a clinical pregnancy following PGT at the Center for Preimplantation Genetic Testing, Aalborg University Hospital, Denmark, between 2017 and 2020.

RESULTS

Chorionic villous sampling was declined by approximately half of the patients. The primary reason for declining was the perceived risk of miscarriage due to the procedure. Nine out of 10 patients responded that they would have opted for a non-invasive prenatal test if it had been offered. Some patients were not aware that the nuchal translucency scan offered to all pregnant women in the early second trimester only rarely provides information on the hereditary disorder for which PGT was performed.

CONCLUSION

Improved counseling on the array of prenatal tests and screenings available might be required to assist patients in making better informed decisions regarding prenatal testing. Non-invasive prenatal testing is welcomed by the patients and will likely increase the number of patients opting for confirmatory prenatal testing following PGT for hereditary disorders.

Catastrophic Human Error in Assisted Reproductive Technologies: A Systematic Review

OBJECTIVE

Assisted reproductive technologies (ARTs) are complex processes with multiple and diverse opportunities for human error. Errors in ART are thought to be rare, but can have devastating consequences for patients and their offspring. The objectives of this article are to review known cases of human error in the ART laboratory and suggest preventative strategies.

METHODS

We performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines using PubMed and Google Scholar databases. Studies were eligible for inclusion if they involved known cases of unintentional human error in the ART laboratory. Only full-text articles in English were included. References of the resulted studies were considered for inclusion.

RESULTS

A total of 420 articles were screened and 37 articles were selected for inclusion. These largely included case reports and reviews in the medical and legal literature. Twenty-two adverse events due to human error in the ART laboratory were identified. Eight of these adverse events were the result of the insemination with the wrong sperm, 6 errors lead to the transfer of the wrong embryo, 3 lead to an error in preimplantation genetic testing, and 5 adverse events lead to the failure of gamete and embryo cryostorage.

CONCLUSIONS

Since the advent of ART, there have been reports of catastrophic events occurring secondary to human error in the laboratory to include incidents of unintended parentage, and have resulted in the loss of embryos and gametes through cryostorage failure. Proposed solutions include the stringent implementation and adherence to safety protocols, adequate laboratory staffing and training, and novel methods for specimen labeling and tracking. Of utmost importance is having knowledge of these errors and the ability to determine cause so that future events can be prevented.

Preimplantation genetic testing for BRCA gene mutation carriers: a cost effectiveness analysis

BACKGROUND

Gynecologic oncologists should be aware of the option of conception through IVF/PGT-M for families with high BRCA related morbidity or mortality. Our objective was to investigate the cost-effectiveness of preimplantation genetic testing for selection and transfer of BRCA negative embryo in BRCA mutation carriers compared to natural conception.

METHODS

Cost-effectiveness of two strategies, conception through IVF/PGT-M and BRCA negative embryo transfer versus natural conception with a 50% chance of BRCA positive newborn for BRCA mutation carriers was compared using a Markovian process decision analysis model. Costs of the two strategies were compared using quality adjusted life years (QALYs'). All costs were discounted at 3%. Incremental cost effectiveness ratio (ICER) compared to willingness to pay threshold was used for cost-effectiveness analysis.

RESULTS

IVF/ PGT-M is cost-effective with an ICER of 150,219 new Israeli Shekels, per QALY gained (equivalent to 44,480 USD), at a 3% discount rate.

CONCLUSIONS

IVF/ PGT-M and BRCA negative embryo transfer compared to natural conception among BRCA positive parents is cost effective and may be offered for selected couples with high BRCA mutation related morbidity or mortality. Our results could impact decisions regarding conception among BRCA positive couples and health care providers.

Can expelled cells/debris from a developing embryo be used for PGT?

BACKGROUND

Preimplantation genetic testing (PGT) is offered to a wide range of structural and numerical chromosomal imbalances, with PGT- polymerase chain reaction (PCR), as the method of choice for amplifying the small DNA content achieved from the blastomere biopsy or trophectoderm (TE) biopsy, that might have a detrimental impact on embryonic implantation potential. Since human embryos cultured until Day-5-6 were noticed to expel cell debris/ fragments within the zona pellucida, we aimed to examine whether these cell debris/ fragments might be used for PGT, as an alternative to embryo biopsy.

METHODS

Blastocysts, which their Day-3 blastomere biopsy revealed an affected embryo with single-gene defect, and following hatching leaved cell debris/fragments within the zona pellucida were analyzed. Each blastocyst and its corresponding cell debris/fragments were separated and underwent the same molecular analysis, based on multiplex PCR programs designed for haplotyping using informative microsatellites markers. The main outcome measure was the intra-embryo congruity of Day-3 blastomere biopsy and its corresponding blastocyst and cell debris/fragments.

RESULTS

Fourteen affected embryos from 9 women were included. Only 8/14 (57.2%) of embryos demonstrated congruent molecular genetic results between Day-3 embryo and its corresponding blastocyst and cell debris/fragments. In additional 6/14 (42.8%) embryos, molecular results of the Day-3 embryos and their corresponding blastocysts were congruent, while the cell debris/fragments yielded no molecular diagnoses (incomplete diagnoses).

CONCLUSIONS

It might be therefore concluded, that in PGT cycles, examining the cell debris/fragments on Day-4, instead of Day-3 blastomere or Day-5 TE biopsies, is feasible and might avoid embryo biopsy with its consequent detrimental effect on embryos' implantation potential. Whenever the latter results in incomplete diagnosis, TE biopsy should be carried out on Day-5 for final genetic results. Further large well-designed studies are required to validate the aforementioned PGT platform.

Impact of preimplantation genetic testing on obstetric and neonatal outcomes: a systematic review and meta-analysis

OBJECTIVE

To investigate whether preimplantation genetic testing (PGT) increases the risk of adverse obstetric and neonatal outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Pregnancies achieved after PGT or in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

INTERVENTION(S)

Systematic search of databases until December 2020 with cross-checking of references from relevant articles in English.

MAIN OUTCOME MEASURE(S)

Obstetric and neonatal outcomes after PGT and IVF/ICSI, including mean birth weight, low birth weight, very low birth weight (VLBW), mean gestational age at birth, preterm birth, very preterm birth, birth defects, intrauterine growth retardation (IUGR), sex ratio, cesarean section, hypertensive disorders of pregnancy, gestational diabetes mellitus, placenta disorder (placenta previa, placenta abruption, placenta accreta), and preterm premature rupture of membranes.

RESULT(S)

Ultimately, a total of 785,445 participants were enrolled in this meta-analysis, and these participants were divided into a PGT group (n = 54,294) and an IVF/ICSI group (n = 731,151). The PGT pregnancies had lower rates of low birth weight (risk ratio [RR] 0.85, 95% confidence interval [CI] 0.75 to 0.98), VLBW (RR 0.52, 95% CI 0.33 to 0.81), and very preterm births (RR 0.55, 95% CI 0.42 to 0.70) than those of IVF/ICSI pregnancies. However, the PGT group had a higher rate of the obstetric outcome of hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.08 to 1.57). The PGT did not increase the risk of other adverse obstetric and neonatal outcomes, such as those associated with mean birth weight, mean gestational age at birth, birth defects, IUGR, sex ratio, cesarean section, gestational diabetes mellitus, placental disorder (placenta previa, placenta abruption, placenta accreta), or preterm premature rupture of membranes. We performed subgroup analysis with only blastocyst biopsies and found that PGT with blastocyst biopsies was associated with a lower rate of VLBW (RR 0.55, 95% CI 0.31 to 0.95). The PGT with blastocyst biopsies did not increase the risk of other adverse obstetric and neonatal outcomes. Additionally, we performed subgroup analysis with only frozen-thawed embryo transfer cycles, and we found that PGT pregnancies were associated with a lower rate of VLBW (RR 0.55, 95% CI 0.31 to 0.97), a lower rate of cesarean birth (RR 0.90, 95% CI 0.82 to 0.99), a higher rate of preterm birth (RR 1.10, 95% CI 1.02 to 1.18), and a higher rate of IUGR (RR 1.21, 95% CI 1.06 to 1.38) than those of IVF/ICSI pregnancies. The PGT with frozen-thawed embryo transfer did not increase the risk of other adverse obstetric and neonatal outcomes.

CONCLUSION(S)

The pooled analysis suggested that PGT did not increase the risk of adverse obstetric outcomes. The association between PGT and a higher risk of IUGR requires further investigation.

Cell-based non-invasive prenatal testing for monogenic disorders: confirmation of unaffected fetuses following preimplantation genetic testing

PURPOSE

Proof of concept of the use of cell-based non-invasive prenatal testing (cbNIPT) as an alternative to chorionic villus sampling (CVS) following preimplantation genetic testing for monogenic disorders (PGT-M).

METHOD

PGT-M was performed by combined testing of short tandem repeat (STR) markers and direct mutation detection, followed by transfer of an unaffected embryo. Patients who opted for follow-up of PGT-M by CVS had blood sampled, from which potential fetal extravillous throphoblast cells were isolated. The cell origin and mutational status were determined by combined testing of STR markers and direct mutation detection using the same setup as during PGT. The cbNIPT results with respect to the mutational status were compared to those of genetic testing of the CVS.

RESULTS

Eight patients had blood collected between gestational weeks 10 and 13, from which 33 potential fetal cell samples were isolated. Twenty-seven out of 33 isolated cell samples were successfully tested (82%), of which 24 were of fetal origin (89%). This corresponds to a median of 2.5 successfully tested fetal cell samples per case (range 1-6). All fetal cell samples had a genetic profile identical to that of the transferred embryo confirming a pregnancy with an unaffected fetus, in accordance with the CVS results.

CONCLUSION

These findings show that although measures are needed to enhance the test success rate and the number of cells identified, cbNIPT is a promising alternative to CVS.

TRIAL REGISTRATION NUMBER

N-20180001.

Maternal and neonatal outcomes following blastocyst biopsy for PGT in single vitrified-warmed embryo transfer cycles

RESEARCH QUESTION

Does blastocyst biopsy for preimplantation genetic testing (PGT) increase the risk of adverse maternal and neonatal outcomes?

STUDY DESIGN

Retrospective cohort study of 5097 single vitrified-warmed blastocyst transfer cycles from January 2016 to December 2018, with 2061 cycles in the biopsied group and 3036 cycles in the unbiopsied group enrolled in the analyses. Maternal and neonatal outcomes were compared between the two groups.

RESULTS

The live birth rate in the biopsied group (41.1%) was significantly higher than that in the unbiopsied group (35.6%, adjusted odds ratio [aOR] 1.27, 95% confidence interval [CI] 1.05-1.54, P = 0.012) after adjusting for maternal age, maternal body mass index, gravidity, parity, infertility diagnosis, timing of blastocyst transfer, blastocyst quality, regimen of endometrial preparation, endometrial thickness before transfer and treatment year. The rates of total pregnancy loss (25.4% versus 32.2%, aOR 0.69, 95% CI 0.52-0.91, P = 0.008) and early miscarriage (12.1% versus 17.3%, aOR 0.56, 95% CI 0.38-0.83, P = 0.004) were significantly lower in the biopsied group than in the unbiopsied group. No significant differences were found in sex ratio or the risks of hypertensive disorders in pregnancy, diabetes in pregnancy, placenta previa, preterm premature rupture of membranes, low birthweight, very low birthweight, macrosomia, small for gestational age, large for gestational age or birth defects between the two groups. When the subgroup analyses were conducted based on different types of PGT, similar patterns were found for all types.

CONCLUSION

Blastocyst biopsy might not increase the risks of adverse maternal and neonatal outcomes in the short term.

ESHRE PGT Consortium data collection XIX-XX: PGT analyses from 2016 to 2017†

STUDY QUESTION

What are the trends and developments in pre-implantation genetic testing (PGT) in 2016–2017 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 19th and 20th data set on PGT are that trophectoderm biopsy has become the main biopsy stage for PGT for aneuploidies (PGT-A) and that the implementation of comprehensive testing technologies is the most advanced with PGT-A.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 18 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

The data for PGT analyses performed between 1 January 2016 and 31 December 2017 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using a new online platform, which is based on genetic analysis as opposed to the former cycle-based format.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on biopsy method, diagnostic technology and clinical outcome were submitted by 61 centres. Records with analyses for more than one PGT for monogenic/single gene defects (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR) indication or with inconsistent data regarding the PGT modality were excluded. All transfers performed within 2 years after the analysis were included enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2016 to 2017 covers a total of 3098 analyses for PGT-M, 1018 analyses for PGT-SR, 4033 analyses for PGT-A and 654 analyses for concurrent PGT-M/SR with PGT-A.

The application of blastocyst biopsy is gradually rising for PGT-M (from 8–12% in 2013–2015 to 19% in 2016–2017), is status quo for PGT-R (from 22–36% in 2013–2015 to 30% in 2016–2017) and has become the preferential biopsy stage for PGT-A (from 23–36% in 2013–2015 to 87% in 2016–2017). For concurrent PGT-M/SR with PGT-A, biopsy was primarily performed at the blastocyst stage (93%). The use of comprehensive diagnostic technology showed a similar trend with a small increased use for PGT-M (from 9–12% in 2013–2015 to 15% in 2016–2017) and a status quo for PGT-SR (from 36–58% in 2013–2015 to 50% in 2016–2017). Comprehensive testing was the main technology for PGT-A (from 66–75% in 2013–2015 to 93% in 2016–2017) and for concurrent PGT-M/SR with PGT-A (93%).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the data submitted by 61 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT in Europe/worldwide, the data sets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Non-invasive preimplantation genetic testing for putative mosaic blastocysts: a pilot study

STUDY QUESTION

What is the potential of applying non-invasive preimplantation genetic testing (niPGT) for chromosome abnormalities in blastocysts reported with a mosaic trophectoderm (TE) biopsy?

SUMMARY ANSWER

niPGT of cell-free DNA in blastocyst culture medium exhibited a good diagnostic performance in putative mosaic blastocysts.

WHAT IS KNOWN ALREADY

Advances in niPGT have demonstrated the potential reliability of cell-free DNA as a resource for genetic assessment, but information on mosaic embryos is scarce because the mosaicism may interfere with niPGT. In addition, the high incidence of mosaicism reported in the context of PGT and the viability of mosaic blastocysts raise questions about whether mosaicism really exists.

STUDY DESIGN, SIZE, DURATION

The study was performed between May 2020 and July 2020. First, clinical data collected by a single-center over a 6-year period on PGT for chromosome aneuploidies (PGT-A) or chromosomal structural rearrangements (PGT-SR) were analyzed. After confirming the reliability of niPGT, 41 blastocysts classified as mosaics by trophectoderm (TE) biopsy were re-cultured. The chromosomal copy number of the blastocyst embryo (BE, the gold standard), TE re-biopsy, and corresponding cell-free DNA in the culture medium was assessed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on patients enrolled for PGT at a single center from 2014 to 2019 were collected and the cycles with available putative mosaic blastocysts were evaluated. To verify the diagnostic validity of niPGT, eight aneuploid blastocysts were thawed and re-cultured for 14-18 h. The concordance of the niPGT diagnosis results and the whole blastocyst testing results was analyzed. Forty-one blastocysts reported as mosaics from 22 patients were included and re-cultured for 14-18 h. The genetic material of the BE, TE re-biopsy, and corresponding cell-free DNA in the culture medium was amplified using multiple annealing and looping-based amplification cycles. The karyotype data from niPGT and TE re-biopsy were compared with that from the whole blastocyst, and the efficiency of niPGT was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

Data on 3738 blastocysts from 785 PGT-A or PGT-SR cycles of 677 patients were collected. According to the TE biopsy report, of the 3662 (98%) successfully amplified samples, 24 (0.6%) yielded no results, 849 (23.2%) were euploid, 2245 (61.3%) were aneuploid, and 544 (14.9%) were mosaic. Sixty patients without euploid blastocysts opted for a single mosaic blastocyst transfer, and 30 (50%) of them obtained a clinical pregnancy. With the BE chromosome copy number as the gold standard, niPGT and TE re-biopsy showed reliable detection ability and diagnostic efficiency in eight putative aneuploid blastocysts. Of the 41 putative mosaic blastocysts re-cultured and re-tested, 35 (85.4%) showed euploid BE results. All but two of the blastocysts previously diagnosed with segmental chromosomal mosaic were actually euploid. In addition, all blastocysts previously classified as low degree (20-50%) mosaics were identified as euploid by BE PGT, whereas four of the six putative high degree (50-80%) mosaic blastocysts showed chromosomal abnormalities. The raw concordance rates of spent culture medium (SCM) and TE re-biopsies compared with BE were 74.4% and 82%, respectively, in terms of overall ploidy and 96.2% and 97.6%, respectively, per single chromosome when considering all degree mosaic results as true positives. However, when we set a mosaicism identification threshold of 50%, the concordance rates of SCM and TE re-biopsies compared with BE were 87.2% and 85% at the overall ploidy level and 98.8% and 98.3% at the chromosomal level, respectively. At the full ploidy level, the sensitivity and false negative rates for niPGT were 100% and 0, respectively. After adjustment of the threshold for mosaicism, the specificity of niPGT increased from 69.7% to 84.8% in terms of overall ploidy and from 96.1% to 98.9% at the chromosomal level.

LIMITATIONS, REASONS FOR CAUTION

The primary limitation of this study is the small sample size, which decreases the strength of our conclusions. If possible, identifying the clinical outcome of niPGT on reassessed mosaic blastocysts would be further progress in this field.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to explore the practicability of niPGT in diagnostic reassessment of putative mosaicism. The present study provides a novel opportunity for patients with only mosaic blastocysts and no euploid blastocysts, regardless of the technical or biological basis of mosaicism. Employing niPGT after 14-18 h of re-culturing might be a superior option for the best use of blastocysts because of its minimally invasive nature.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from National Key Technology Research and Development Program of China (No. 2017YFC1002004), the Central Guiding the Science and Technology Development of the Local (2018080802D0081) and College Natural Science Project of Anhui Province (KJ2019A0287). There are no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Prenatal diagnostic techniques and IVF in patients with coagulopathies

Hemophilia and other hereditary coagulopathies tend to be associated with a huge negative impact both for individuals who suffer the disease and for their families. In this respect, hemophilia carriers feel the need to make reproductive decisions which will inevitably affect their children, their families and from themselves. Genetic and reproductive counseling is of the essence to alleviate these women's distress. Prenatal diagnosis and preimplantation genetic diagnosis (PGD) allow couples at high-risk of transmitting genetic diseases like hemophilia and other hereditary coagulopathies to prevent the birth of children with the disease. The main difference between prenatal diagnosis and PGD is related to the time at which diagnosis is made. Prenatal diagnosis is done when the woman is pregnant, and both the performance of the technique and its result can affect the course of pregnancy. PGD is a diagnostic procedure in which embryos created in vitro are analyzed for genetic defects before being transferred to the uterus. Performance of both prenatal diagnosis and PGD is subject to a few prerequisites: the establishment of an exact clinical diagnosis, an understanding of the parental genetic alterations that are responsible for the disease and technical feasibility of genetic diagnosis. These couples should be provided with complete, up-to-date and easy-to-understand information.

A review on the motivations, decision-making factors, attitudes and experiences of couples using pre-implantation genetic testing for inherited conditions

BACKGROUND

In pre-implantation genetic testing (PGT), fertile couples undergo IVF with genetic testing of embryos to avoid conceptions with a genetic condition. There is an exponentially increasing uptake with over 600 applications listed by the Human Fertilisation and Embryology Authority in the UK. The psychological aspects of the decision-making process and the experience of PGT, however, are relatively underevaluated, with the potential to leave patients unsupported in their journeys.

OBJECTIVE AND RATIONALE

In this review, we aim to comprehensively report on every aspect of couples' experiences of PGT. We consider what motivates users, the practical and ethical decisions involved and how couples navigate the decision-making process. Additionally, we report on the social and psychological impact on couples who are actively undergoing or have completed the PGT process.

SEARCH METHODS

A systematic search of English peer-reviewed journals of three computerized databases was undertaken following PRISMA guidelines. Studies that examined the motivations, attitudes, decision-making factors and experiences of patients who have been actively engaged in the PGT process were included. No restrictions were placed on study design or date of publication. Studies examining patients using PGT in a hypothetical context or solely using PGT for aneuploidy were excluded. Qualitative data were extracted using thematic analysis.

OUTCOMES

The main outcomes were patient motivations, deciding factors and attitudes, as well as the patient experience of coming to a decision and going through PGT.Patients were primarily motivated by the desire to have a healthy child and to avoid termination of pregnancy. Those with a sick child or previous experience of termination were more likely to use PGT. Patients also felt compelled to make use of the technology available, either from a moral responsibility to do so or to avoid feelings of guilt if not. The main factors considered when deciding to use PGT were the need for IVF and the acceptability of the technology, the financial cost of the procedure and one's ethical standpoint on the creation and manipulation of embryos. There was a general consensus that PGT should be applied to lethal or severe childhood disease but less agreement on use for adult onset or variable expression conditions. There was an agreement that it should not be used to select for aesthetic traits and a frustration with the views of PGT in society. We report that couples find it difficult to consider all of the benefits and costs of PGT, resulting in ambivalence and prolonged indecision. After deciding on PGT use, we found that patients find the process extremely impractical and psychologically demanding.

WIDER IMPLICATIONS

This review aimed to summarize the current knowledge on how patients decide to use and experience PGT and to make suggestions to incorporate the findings into clinical practice. We cannot stress enough the importance of holistic evaluation of patients and thorough counselling prior to and during PGT use from a multidisciplinary team that includes geneticists, IVF clinicians, psychologists and also patient support groups. Large prospective studies using a validated psychological tool at various stages of the PGT process would provide an invaluable database for professionals to better aid patients in their decision-making and to improve the patient experience.

Embryo biopsy and perinatal outcomes of singleton pregnancies: an analysis of 16,246 frozen embryo transfer cycles reported in the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System

BACKGROUND

Preimplantation genetic testing is commonly performed by removing cells from the trophectoderm, the outer layer of the blastocyst, which subsequently forms the placenta. Because preimplantation genetic testing removes the cells that are destined to form the placenta, it is possible that preimplantation genetic testing could be associated with an increased risk for adverse outcomes associated with abnormal placentation. Despite the increasing utilization of preimplantation genetic testing, few studies have investigated the perinatal outcomes, with published studies yielding contradictory findings and using small sample sizes.

OBJECTIVE

This study aimed to compare the perinatal outcomes of singleton pregnancies conceived following frozen embryo transfer of a single, autologous blastocyst either with or without preimplantation genetic testing.

STUDY DESIGN

This was a retrospective analysis of autologous frozen embryo transfer cycles that led to singleton live births per the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System, including cycles initiated between 2014 and 2015. The perinatal outcomes, including birthweight, Z-score, small for gestational age, large for gestational age, macrosomia, and preterm birth, were compared between pregnancies with or without preimplantation genetic testing. We conducted multivariable linear regression analyses for the birthweight and Z-score and logistic regression for the binary outcomes. A false discovery rate was adjusted to decrease the type I error from multiple hypothesis testing.

RESULTS

Of the 16,246 frozen embryo transfers resulting in singleton births included in this analysis, 6244 involved the transfer of a single blastocyst that had undergone preimplantation genetic testing, and the remainder (n=10,002) involved the transfer of a single blastocyst that had not undergone a biopsy. When compared with the women from the nonpreimplantation genetic testing group, the average maternal age (35.8±4.1 vs 33.7±3.9; P<.001) and prevalence of prior spontaneous abortion (37.3% vs 27.7%; P<.001) were higher among women from the preimplantation genetic testing group. Bivariate analysis revealed a higher prevalence of small-for-gestational-age newborns (4.8% vs 4.0%; P=.008) and premature delivery (14.1% vs 12.5%; P=.005) and a lower prevalence of large-for-gestational-age newborns (16.3% vs 18.2%; P=.003) and macrosomia (11.1% vs 12.4%; P=.013) among the preimplantation genetic testing pregnancies. Multivariate regression analyses, adjusting for the year of transfer, maternal age, maternal body mass index, smoking status (3 months before the treatment cycle), obstetrical histories (full-term birth, preterm birth, and spontaneous abortion), infertility diagnosis, and infant sex suggested a significantly increased odds of preterm birth (adjusted odds ratio, 1.20; 95% confidence interval, 1.09-1.33; P<.001) from preimplantation genetic testing blastocysts. Birthweight (-14.63; 95% confidence interval, -29.65 to 0.38; P=.056), birthweight Z-score (-0.03; 95% confidence interval, -0.06 to 0.00; P=.081), and odds of small-for-gestational-age newborns (adjusted odds ratio, 1.17; 95% confidence interval, 0.99-1.38; P=.066), large-for-gestational-age newborns (adjusted odds ratio, 0.96; 95% confidence interval, 0.88-1.06; P=.418), and macrosomia (adjusted odds ratio, 0.96; 95% confidence interval, 0.85-1.07; P=.427) did not differ between the frozen transfer cycles with or without preimplantation genetic testing in the analysis adjusted for the confounders. Subgroup analysis of the cycles with a stated infertility diagnosis (n=14,285) yielded consistent results.

CONCLUSION

Compared with frozen embryo transfer cycles without preimplantation genetic testing, the frozen embryo transfer cycles with preimplantation genetic testing was associated with a small increase in the likelihood of preterm birth. Although the increase in the risk for prematurity was modest in magnitude, further investigation is warranted.

The status of preimplantation genetic testing in the UK and USA

STUDY QUESTION

Has the number of preimplantation genetic testing (PGT) cycles in the UK and USA changed between 2014 and 2016?

SUMMARY ANSWER

From 2014 to 2016, the number of PGT cycles in the UK has remained the same at just under 2% but in the USA has increased from 13% to 27%.

WHAT IS KNOWN ALREADY

PGT was introduced as a treatment option for couples at risk of transmitting a known genetic or chromosomal abnormality to their child. This technology has also been applied as an embryo selection tool in the hope of increasing live birth rates per transfer. ART cycles are monitored in the UK by the Human Fertilisation and Embryology Authority (HFEA) and in the USA by the Society for Assisted Reproductive Technology (SART). Globally, data are monitored via the ESHRE PGT Consortium.

STUDY DESIGN, SIZE, DURATION

This cross-sectional study used the HFEA and SART databases to analyse PGT cycle data and make comparisons with IVF data to examine the success of and changes in patient treatment pathways. Both data sets were analysed from 2014 to 2016. The UK data included 3385 PGT cycles and the USA data included 94 935 PGT cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Following an extensive review of both databases, filters were applied to analyse the data. An assessment of limitations of each database was also undertaken, taking into account data collection by the ESHRE PGT Consortium. In the UK and USA, the publicly available information from these datasets cannot be separated into different indications.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of PGT cycles as a total of ART procedures has remained the same in the UK but increased annually in the USA from 13% to 27%. Between 2014 and 2016 inclusive, 3385 PGT cycles have been performed in the UK, resulting in 1074 PGT babies being born. In the USA 94 935 PGT cycles have been performed, resulting in 26 822 babies being born. This gave a success rate per egg collection for PGT of 32% for the UK and 28% for the USA. Analysis of the data by maternal age shows very different patient populations between the UK and USA. These differences may be related to the way PGT is funded in the UK and USA and the lack of HFEA support for PGT for aneuploidy.

LIMITATIONS, REASONS FOR CAUTION

Data reported by the HFEA and SART have different limitations. As undertaken by the ESHRE PGT Consortium, both data sets should separate PGT data by indication. Although the HFEA collects data from all IVF clinics in the UK, SART data only represent 83% of clinics in the USA.

WIDER IMPLICATIONS OF THE FINDINGS

Worldwide, a consistent reporting scheme is required in which success rates can convey the effectiveness of PGT approaches for all indications.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained and there are no competing interests to declare that are directly related to this project. Joyce Harper is the director of the Embryology and PGD Academy, which offers education in these fields.

Identity-by-state-based haplotyping expands the application of comprehensive preimplantation genetic testing

STUDY QUESTION

Is it possible to haplotype parents using parental siblings to leverage preimplantation genetic testing (PGT) for monogenic diseases and aneuploidy (comprehensive PGT) by genome-wide haplotyping?

SUMMARY ANSWER

We imputed identity-by-state (IBS) sharing of parental siblings to phase parental genotypes.

WHAT IS KNOWN ALREADY

Genome-wide haplotyping of preimplantation embryos is being implemented as a generic approach for genetic diagnosis of inherited single-gene disorders. To enable the phasing of genotypes into haplotypes, genotyping the direct family members of the prospective parent carrying the mutation is required. Current approaches require genotypes of either (i) both or one of the parents of the affected prospective parent or (ii) an affected or an unaffected child of the couple. However, this approach cannot be used when parents or children are not attainable, prompting an investigation into alternative phasing options.

STUDY DESIGN, SIZE, DURATION

This is a retrospective validation study, which applied IBS-based phasing of parental haplotypes in 56 embryos derived from 12 PGT families. Genome-wide haplotypes and copy number profiles generated for each embryo using the new phasing approach were compared with the reference PGT method to evaluate the diagnostic concordance.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study included 12 couples with a known hereditary genetic disorder, participating in the comprehensive PGT program and with at least one parental sibling available (e.g. brother and/or sister). Genotyping data from both prospective parents and the parental sibling(s) were used to perform IBS-based phasing and to trace the disease-associated alleles. The outcome of the IBS-based PGT was compared with the results of the clinically implemented reference haplotyping-based PGT method.

MAIN RESULTS AND THE ROLE OF CHANCE

IBS-based haplotyping was performed for 12 PGT families. In accordance with the theoretical prediction of allele sharing between sibling pairs, 6 out of 12 (50%) couples or 23 out of 56 embryos could be phased using parental siblings. In families where phasing was possible, haplotype calling in the locus of interest was 100% concordant between the reference PGT method and IBS-based approach using parental siblings.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Phasing of parental haplotypes will only be possible when the disease locus lies in an informative region (categorized as IBS1). Phasing prospective parents using relatives with reduced genetic relatedness as a reference (e.g. siblings) decreases the size and the occurrence of informative IBS1 regions, necessary for haplotype calling. By including more than one extended family member, the chance of obtaining IBS1 coverage in the interrogated locus can be increased. A pre-PGT work-up can define whether the carrier couple could benefit from this approach.

WIDER IMPLICATIONS OF THE FINDINGS

Phasing by relatives extends the potential of comprehensive PGT, since it allows the inclusion of couples who do not have access to the standard phasing references, such as parents or offspring.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the KU Leuven grant (C14/18/092), Research Foundation Flanders (FWO; GA09311N), Horizon 2020 innovation programme (WIDENLIFE, 692065) and Agilent Technologies. J.R.V., T.V. and M.Z.E. are co-inventors of a patent ZL910050-PCT/EP2011/060211-WO/2011/157846 'Methods for haplotyping single-cells' and ZL913096-PCT/EP2014/068315-WO/2015/028576 'Haplotyping and copy number typing using polymorphic variant allelic frequencies' licensed to Agilent Technologies. The other authors have no conflict of interest to declare.

Utilization of preimplantation genetic testing in the USA

PURPOSE

To evaluate the use of preimplantation genetic testing (PGT) and live birth rates (LBR) in the USA from 2014 to 2017 and to understand how PGT is being used at a clinic and state level.

METHODS

This study accessed SART data for 2014 to 2017 to determine LBR and the CDC for years 2016 and 2017 to identify PGT usage. Primary cycles included only the first embryo transfer within 1 year of an oocyte retrieval; subsequent cycles included transfers occurring after the first transfer or beyond 1 year of oocyte retrieval.

RESULTS

In the SART data, the number of primary PGT cycles showed a significant monotonic annual increase from 18,805 in 2014 to 54,442 in 2017 (P = 0.042) and subsequent PGT cycles in these years increased from 2946 to 14,361 (P = 0.01). There was a significant difference in primary PGT cycle use by age, where younger women had a greater percentage of PGT treatment cycles than older women. In both PGT and non-PGT cycles, the LBR per oocyte retrieval decreased significantly from 2014 to 2017 (P<0001) and younger women had a significantly higher LBR per oocyte retrieval compared to older women (P < 0.001). The CDC data revealed that in 2016, just 53 (11.4%) clinics used PGT for more than 50% of their cycles, which increased to 99 (21.4%) clinics in 2017 (P< 0.001).

CONCLUSIONS

A growing number of US clinics are offering PGT to their patients. These findings support re-evaluation of the application for PGT.

Successful birth after preimplantation genetic testing for a couple with two different reciprocal translocations and review of the literature

BACKGROUND

Preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) is widely applied in couples with single reciprocal translocation to increase the chance for a healthy live birth. However, limited knowledge is known on the data of PGT-SR when both parents have a reciprocal translocation. Here, we for the first time present a rare instance of PGT-SR for a non-consanguineous couple in which both parents carried an independent balanced reciprocal translocation and show how relevant genetic counseling data can be generated.

METHODS

The precise translocation breakpoints were identified by whole genome low-coverage sequencing (WGLCS) and Sanger sequencing. Next-generation sequencing (NGS) combining with breakpoint-specific polymerase chain reaction (PCR) was used to define 24-chromosome and the carrier status of the euploid embryos.

RESULTS

Surprisingly, 2 out of 3 day-5 blastocysts were found to be balanced for maternal reciprocal translocation while being normal for paternal translocation and thus transferable. The transferable embryo rate was significantly higher than that which would be expected theoretically. Transfer of one balanced embryo resulted in the birth of a healthy boy.

CONCLUSION(S)

Our data of PGT-SR together with a systematic review of the literature should help in providing couples carrying two different reciprocal translocations undergoing PGT-SR with more appropriate genetic counseling.

Heritable human genome editing: Research progress, ethical considerations, and hurdles to clinical practice

Our genome at conception determines much of our health as an adult. Most human diseases have a heritable component and thus may be preventable through heritable genome editing. Preventing disease from the beginning of life before irreversible damage has occurred is an admirable goal, but the path to fruition remains unclear. Here, we review the significant scientific contributions to the field of human heritable genome editing, the unique ethical challenges that cannot be overlooked, and the hurdles that must be overcome prior to translating these technologies into clinical practice.

Should germline genome editing be allowed? The effect of treatment characteristics on public acceptability

STUDY QUESTION

To what extent do characteristics of germline genome editing (GGE) determine whether the general public supports permitting the clinical use of GGE?

SUMMARY ANSWER

The risk that GGE would cause congenital abnormalities had the largest effect on support for allowing GGE, followed by effectiveness of GGE, while costs, the type of application (disease or enhancement) and the effect on child well-being had moderate effects.

WHAT IS KNOWN ALREADY

Scientific progress on GGE has increased the urgency of resolving whether and when clinical application of GGE may be ethically acceptable. Various expert bodies have suggested that the treatment characteristics will be key in determining whether GGE is acceptable. For example, GGE with substantial risks (e.g. 15% chance of a major congenital abnormality) may be acceptable to prevent a severe disease but not to enhance non-medical characteristics or traits of an otherwise healthy embryo (e.g. eye colour or perhaps in the future more complex traits, such as intelligence). While experts have called for public engagement, it is unclear whether and how much the public acceptability of GGE is affected by the treatment characteristics proposed by experts.

STUDY DESIGN, SIZE, DURATION

The vignette-based survey was disseminated in 2018 among 1857 members of the Dutch general public. An online research panel was used to recruit a sample representing the adult Dutch general public.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature review identified the key treatment characteristics of GGE: the effect on the well-being of the future child, use for disease or enhancement, risks for the future child, effectiveness (here defined as the chance of a live birth, assuming that if the GGE was not successful, the embryo would not be transferred), cost and availability of alternative treatments/procedures to prevent the genetic disease or provide enhancement (i.e. preimplantation genetic testing (PGT)), respectively. For each treatment characteristic, 2-3 levels were defined to realistically represent GGE and its current alternatives, donor gametes and ICSI with PGT. Twelve vignettes were created by fractional factorial design. A multinominal logit model assessed how much each treatment characteristic affected participants' choices.

MAIN RESULTS AND THE ROLE OF CHANCE

The 1136 respondents (response rate 61%) were representative of the Dutch adult population in several demographics. Respondents were between 18 and 89 years of age. When no alternative treatment/procedure is available, the risk that GGE would cause (other) congenital abnormalities had the largest effect on whether the Dutch public supported allowing GGE (coefficient = -3.07), followed by effectiveness (coefficient = 2.03). Costs (covered by national insurance, coefficient = -1.14), the type of application (disease or enhancement; coefficient = -1.07), and the effect on child well-being (coefficient = 0.97) had similar effects on whether GGE should be allowed. If an alternative treatment/procedure (e.g. PGT) was available, participants were not categorically opposed to GGE, however, they were strongly opposed to using GGE for enhancement (coefficient = -3.37). The general acceptability of GGE was higher than participants' willingness to personally use it (P < 0.001). When participants considered whether they would personally use GGE, the type of application (disease or enhancement) was more important, whereas effectiveness and costs (covered by national insurance) were less important than when they considered whether GGE should be allowed. Participants who were male, younger and had lower incomes were more likely to allow GGE when no alternative treatment/procedure is available.

LIMITATIONS, REASONS FOR CAUTION

Some (e.g. ethnic, religious) minorities were not well represented. To limit complexity, not all characteristics of GGE could be included (e.g. out-of-pocket costs), therefore, the views gathered from the vignettes reflect only the choices presented to the respondents. The non-included characteristics could be connected to and alter the importance of the studied characteristics. This would affect how closely the reported coefficients reflect 'real-life' importance.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to quantify the substantial impact of GGE's effectiveness, costs (covered by national insurance), and effect on child well-being on whether the public considered GGE acceptable. In general, the participants were strikingly risk-averse, in that they weighed the risks of GGE more heavily than its benefits. Furthermore, although only a single study in one country, the results suggests that-if sufficiently safe and effective-the public may approve of using GGE (presumably combined with PGT) instead of solely PGT to prevent passing on a disease. The reported public views can serve as input for future consideration of the ethics and governance of GGE.

STUDY FUNDING/COMPETING INTEREST(S)

Young Academy of the Royal Dutch Academy of Sciences (UPS/RB/745), Alliance Grant of the Amsterdam Reproduction and Development Research Institute (2017-170116) and National Institutes of Health Intramural Research Programme. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Pre-implantation genetic testing: Past, present, future

BACKGROUND

Pre-implantation genetic testing (PGT) has been performed worldwide since it was first used by Handyside et al in the United Kingdom to sex embryos in 1990. Until about 2010, cleavage stage embryo biopsy and fluorescent in situ hybridization (FISH) were mainstream; however, in 2012, blastocyst biopsy (trophectoderm; TE biopsy) became mainstream. In addition, array comparative genomic hybridization (aCGH) was used for analysis and further evolved to next-generation sequencing (NGS), which is used worldwide.

METHODS

PGT for reciprocal balanced translocation and Robertsonian translocation (PGT-SR) was approved in Japan for habitual abortion to reduce pregnancy loss, and since 2008, we have been performing PGT-SR using cleavage stage embryos and FISH. In 2014, we performed TE biopsy and NGS analysis.

MAIN FINDINGS

In this paper, I separately described the details of our methods and clinical results of FISH and NGS. NGS is superior to FISH because it can detect all chromosomes.

CONCLUSION

TE biopsy and NGS, which have recently become mainstream, have stable outcomes, because TE biopsy yields more cells and fewer mosaics than the cleavage stage. As a result, diagnoses are more reliable, resulting in higher pregnancy rates and lower abortion rates.

Preimplantation genetic testing for carriers of BRCA1/2 pathogenic variants

The detection of germline BRCA1/2 pathogenic variant has relevant implications for the patients and their family members. Family planning, prophylactic surgery and the possibility of preimplantation genetic testing for monogenic disorders (PGT-M) to avoid transmittance of pathogenic variants to the offspring are relevant topics in this setting. PGT-M is valuable option for BRCA carriers, but it remains a controversial and underdiscussed topic. Although the advances in PGT technologies have improved pregnancy rate, there are still several important challenges associated with its use. The purpose of this review is to report the current evidence on PGT-M for BRCA1/2 carriers, ethical concerns and controversy associated with its use, reproductive implications of BRCA pathogenic variants, underlying areas in which an educational effort would be beneficial as well as possibilities for future research efforts in the field.

Review: Preimplantation genetic diagnosis (PGD) as a reproductive option in patients with neurodegenerative disorders

Preimplantation genetic diagnosis (PGD) was introduced in the late 1980s and represents an option for couples at risk of transmitting an inherited, debilitating or neurological disorder to their children. From a cleavage or blastocyst stage embryo, cell(s) are collected and then genetically analyzed for disease; enabling an unaffected embryo to be transferred into the uterus cavity. Nowadays, PGD has been carried out for several hundreds of heritable conditions including myotonic dystrophy, and for susceptibility genes involved in cancers of the nervous system. Currently, advanced molecular technologies with better resolution, such as array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing, are on the verge of becoming the gold standard in embryo preimplantation screening. Given this, it may be time for neurological societies to consider the published evidence to develop new guidelines for the integration of PGD into modern preventative neurology. Therefore, the main aim of this review is to illustrate the option of PGD to enable conception of an unaffected baby, and to assist clinicians and neurologists in the counseling of the patient at risk of transmitting an inherited disease, to explore the genetic journey throughout in vitro fertilization IVF with PGD.

Obstetric and Perinatal Outcomes in Pregnancies Conceived After Preimplantation Genetic Testing for Monogenetic Diseases

OBJECTIVE

To investigate whether the addition of embryo biopsy performed during preimplantation genetic testing for monogenic diseases is associated with a higher risk of obstetric and neonatal complications compared with in vitro fertilization (IVF) without preimplantation genetic testing or spontaneously conceived pregnancies.

METHODS

This is a cohort study of all pregnancies conceived after preimplantation genetic testing for monogenic diseases (PGT-M group) from 2006 to 2018 at Sheba Medical Center, Israel. The control groups included patients who had conceived spontaneously (spontaneous conception group) or by IVF without preimplantation genetic testing (IVF group) and delivered at Sheba Medical Center. The obstetrics outcomes were compared among the groups. Multivariable regression modeling was performed, focusing on the relationship between preimplantation genetic testing and adverse outcomes.

RESULTS

Final analysis included 345 singleton and 76 twin deliveries in the PGT-M group. The spontaneous conception group included 5,290 singleton and 92 twin deliveries. The IVF group included 422 singleton and 101 twin deliveries. Among singleton pregnancies, patients in the PGT-M group had a higher rate of hypertensive disorders (6.9%) compared with those in the spontaneous conception group (2.3%; odds ratio [OR] 3.3; 95% CI 1.9-4.8; adjusted odds ratio [aOR] 14.8; 95% CI 7.4-29.8) and the IVF group (4.7%; OR 1.5; 95% CI 0.8-2.7; aOR 5.9; 95% CI 1.9-18.2). Likewise, patients in the PGT-M group had a higher rate of small-for-gestational age neonates (12.4%) compared with those in the spontaneous conception group (3.9%; OR 3.4; 95% CI 2.4-4.9; aOR 2.3; 95% CI 1.5-3.4) and the IVF group (4.5%; OR 3; 95% CI 1.7-5.2; aOR 2.5; 95% CI 1.7-5.2). Among twin pregnancies, patients in the PGT-M group also had an increased rate of hypertensive disorders compared with those in the spontaneous conception group (4.3%; OR 4.1; 95% CI 1.2-13.3; aOR 10.9; 95% CI 2.3-50) and the IVF group (4%; OR 4.5; 95% CI 1.4-14.7; aOR 3.7; 95% CI 1.1-12.8).

CONCLUSION

Pregnancies conceived after preimplantation genetic testing for monogenic disorders were associated with an increased risk of obstetric complications compared with pregnancies conceived spontaneously or by IVF without preimplantation genetic testing.

Reanalysis of discarded blastocysts for autosomal aneuploidy after sex selection in cleavage-stage embryos

Objective

The goal of the present study was to investigate the rate of chromosomal aneuploidies in surplus embryos after sex determination at the cleavage stage. Then, the same chromosomal aneuploidies were evaluated in blastocysts after extended culture.

Methods

Sixty-eight surplus embryos were biopsied at the cleavage stage and incubated for an additional 3 days to allow them to reach the blastocyst stage. The embryos were reanalyzed via fluorescence in situ hybridization (FISH) to examine eight chromosomes (13, 15, 16, 18, 21, 22, X, and Y) in both cleavage-stage embryos and blastocysts.

Results

Although the total abnormality rate was lower in blastocysts (32.35%) than in cleavage-stage embryos (45.58%), the difference was not significant (p=0.113). However, when we restricted the analysis to autosomal abnormalities, we observed a significant difference in the abnormality rate between the cleavage-stage embryos (44.11%) and the blastocysts (17.64%, p=0.008). A higher rate of sex chromosomal abnormalities was also observed in cleavage-stage embryos (29.4%) than in blastocysts (14.70%, p=0.038).

Conclusion

The data indicated that embryo biopsy should be conducted at the blastocyst stage rather than the cleavage stage. The results also emphasized that examination of common chromosomal aneuploidies apart from sex selection cycles can be conducted in the blastocyst stage with the FISH method.

[Pre-implantation genetic testing: Comparison between cleavage stage and blastocyst biopsy]

OBJECTIVES

Preimplantation genetic testing (PGT) refers to the set of techniques for testing whether embryos obtained through in vitro fertilization have genetic defect. There is a lack of global standardization regarding practices between countries or even from one center to another. In ours, biopsies are preferably performed on day 3 embryos, but also at the blastocyst stage on day 5. The blastocyst biopsy often requires systematic freezing of the embryos before obtaining the genetic results, whereas day 3 biopsy allows fresh embryo transfer of the healthy or balanced embryo after getting the genetic results. We wanted to compare the chances of success for couples performing PGT in our center according to the day of the biopsy.

METHODS

For this, we carried out a retrospective monocentric study including all PGT cycles performed between 2016 and 2019 divided into two groups: day 3 or day 5 biopsy.

RESULTS

There was no significant difference in terms of live birth rate (P=0.7375) after fresh embryo transfers, as well for pregnancy rates, clinical pregnancy rates, implantation rates and miscarriage rates. On the other hand, we observed higher live birth rates after frozen-thawed embryo transfer when the biopsy was performed on day 5 rather on day 3 (P=0.0001). We also wanted to assess what was the most efficient biopsy strategy in our laboratory. Our rates of useful embryos were similar regardless of the day of the biopsy (34% in D3 and 37.7% in D5, P=0.244). No statistical difference was found in the number of unnecessarily biopsied embryos in the two groups. But still, the percentage of embryos biopsied on D5 and immediately frozen was 42.8% (118 blastocysts), while no embryo biopsied on D3 led to this case.

CONCLUSION

Therefore, our results are in favor of generalization of the D5 biopsy as the international standard. However, the organizational, financial and logistical implications that this technic would impose make it unsystematic in our center.

Development and clinical application of a preimplantation genetic testing for monogenic disease (PGT-M) for beta thalassemia in Vietnam

Purpose

The purpose of this research is to study the clinical outcomes using a next-generation sequencing-based protocol allowing for simultaneous testing of mutations in the beta thalassemia (HBB) gene, including single nucleotide polymorphism (SNP) markers for PGT-M along with low-pass whole genome analysis of chromosome aneuploidies for PGT-A.

Methods

A combined PGT-M (thalassemia) plus PGT-A system was developed for patients undergoing IVF in Vietnam. Here we developed a system for testing numerous thalassemia mutations plus SNP-based testing for backup mutation analysis and contamination control using next-generation sequencing (NGS). Low -pass next-generation sequencing was used to assess aneuploidy in some of the clinical PGT cases. Patients underwent IVF followed by embryo biopsy at the blastocyst stage for combined PGT-A/M.

Results

Two cases have completed the entire process including transfer of embryos, while a further nine cases have completed the IVF and PGT-M/A analysis but have not completed embryo transfer. In the two cases with embryo transfer, both patients achieved pregnancy with an unaffected, euploid embryo confirmed through prenatal diagnosis. In the further nine cases, 39 embryos were biopsied and all passed QC for amplification. There were 8 unaffected embryos, 31 carrier embryos, and 11 affected embryos. A subset of 24 embryos also had PGT-A analysis with 22 euploid embryos and 2 aneuploid embryos.

Conclusions

Here we report the development and clinical application of a combined PGT-M for HBB and PGT-A for gross chromosome aneuploidies from 11 patients with detailed laboratory findings along with 2 cases that have completed embryo transfer.

A novel monogenic preimplantation genetic testing strategy for sporadic polycystic kidney caused by de novo PKD1 mutation

Autosomal dominant hereditary polycystic kidney disease (ADPKD) is the most common inherited kidney disease that causes end-stage renal disease and kidney failure. Preimplantation genetic testing for monogenic (PGT-M) can effectively prevent the transmission of genetic diseases from parents to the offspring before pregnancy. However, PGT-M currently adopts the single nucleotide polymorphism (SNP) linkage analysis for embryo's pathogenic gene carrying status and linkage analysis requires proband of the family. Here we report a new PGT-M strategy using single sperm SNP linkage analysis for male patient with sporadic ADPKD caused by de novo PKD1 mutation. We recruited five couples with male patient with ADPKD caused by de novo PKD1 mutation, and 39 embryos from six PGT-M cycles were detected. The five couples had at least one embryo that does not carry the PKD1 mutation. Within these five couples, the accuracy of carrier status of embryos was confirmed by amniotic fluid gene detection of two couples and two couples successfully delivered healthy fetuses. Therefore, the new PGT-M strategy of using single sperm SNP linkage analysis was proved to be feasible and effective for male patient with ADPKD caused by de novo PKD1 mutation.

Preconception genome medicine: current state and future perspectives to improve infertility diagnosis and reproductive and health outcomes based on individual genomic data

BACKGROUND

Our genetic code is now readable, writable and hackable. The recent escalation of genome-wide sequencing (GS) applications in population diagnostics will not only enable the assessment of risks of transmitting well-defined monogenic disorders at preconceptional stages (i.e. carrier screening), but also facilitate identification of multifactorial genetic predispositions to sub-lethal pathologies, including those affecting reproductive fitness. Through GS, the acquisition and curation of reproductive-related findings will warrant the expansion of genetic assessment to new areas of genomic prediction of reproductive phenotypes, pharmacogenomics and molecular embryology, further boosting our knowledge and therapeutic tools for treating infertility and improving women's health.

OBJECTIVE AND RATIONALE

In this article, we review current knowledge and potential development of preconception genome analysis aimed at detecting reproductive and individual health risks (recessive genetic disease and medically actionable secondary findings) as well as anticipating specific reproductive outcomes, particularly in the context of IVF. The extension of reproductive genetic risk assessment to the general population and IVF couples will lead to the identification of couples who carry recessive mutations, as well as sub-lethal conditions prior to conception. This approach will provide increased reproductive autonomy to couples, particularly in those cases where preimplantation genetic testing is an available option to avoid the transmission of undesirable conditions. In addition, GS on prospective infertility patients will enable genome-wide association studies specific for infertility phenotypes such as predisposition to premature ovarian failure, increased risk of aneuploidies, complete oocyte immaturity or blastocyst development failure, thus empowering the development of true reproductive precision medicine.

SEARCH METHODS

Searches of the literature on PubMed Central included combinations of the following MeSH terms: human, genetics, genomics, variants, male, female, fertility, next generation sequencing, genome exome sequencing, expanded carrier screening, secondary findings, pharmacogenomics, controlled ovarian stimulation, preconception, genetics, genome-wide association studies, GWAS.

OUTCOMES

Through PubMed Central queries, we identified a total of 1409 articles. The full list of articles was assessed for date of publication, limiting the search to studies published within the last 15 years (2004 onwards due to escalating research output of next-generation sequencing studies from that date). The remaining articles' titles were assessed for pertinence to the topic, leaving a total of 644 articles. The use of preconception GS has the potential to identify inheritable genetic conditions concealed in the genome of around 4% of couples looking to conceive. Genomic information during reproductive age will also be useful to anticipate late-onset medically actionable conditions with strong genetic background in around 2-4% of all individuals. Genetic variants correlated with differential response to pharmaceutical treatment in IVF, and clear genotype-phenotype associations are found for aberrant sperm types, oocyte maturation, fertilization or pre- and post-implantation embryonic development. All currently known capabilities of GS at the preconception stage are reviewed along with persisting and forthcoming barriers for the implementation of precise reproductive medicine.

WIDER IMPLICATIONS

The expansion of sequencing analysis to additional monogenic and polygenic traits may enable the development of cost-effective preconception tests capable of identifying underlying genetic causes of infertility, which have been defined as 'unexplained' until now, thus leading to the development of a true personalized genomic medicine framework in reproductive health.

Comparison of PGS2.0 versus conventional embryo morphology evaluation for patients with recurrent pregnancy loss: a study protocol for a multicentre randomised trial

INTRODUCTION

Pregnancy loss (PL) is an adverse life event, and there is no proven effective treatment for recurrent PL (RPL). Preimplantation genetic screening (PGS) can be performed to reduce the risks of PL; however, there is still no solid scientific evidence that PGS improves outcomes for couples experiencing RPL. Comprehensive chromosome screening (PGS2.0) has become a routine practice in in vitro fertilisation (IVF) clinics. Previous studies based on PGS1.0 with a focus on RPL couples where the female is of advanced maternal age have reported contradictory results. Hence, a multicentre randomised trial is needed to provide evidence for the clinical benefits of PGS2.0 treatment for RPL couples.

METHODS AND ANALYSIS

Overall, 268 RPL couples undergoing IVF cycles will be enrolled. Couples will be randomised according to a unique grouping number generated by a random digital software into (1) PGS2.0 group and (2) non-PGS (conventional embryo morphology evaluation) group. This study aims to investigate whether the live birth rate (LBR) per initiated cycle after PGS2.0 is superior to the LBR per initiated cycle after conventional embryo evaluation (non-PGS group). Live birth will be defined as a live baby born after a gestation period of >28 weeks, with a birth weight of more than 1000 g. A multivariate logistic regression model will be used to adjust for confounding factors.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Ethics Committee of Obstetrics and Gynecology Hospital, Fudan University and the participating hospitals. Written informed consent will be obtained from each couple before any study procedure is performed. Data from this study will be stored in the Research Electronic Data Capture. The results of this trial will be presented and published via peer-reviewed publications and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT03214185; Pre-results.

ESHRE PGT Consortium data collection XVI-XVIII: cycles from 2013 to 2015

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2013–2015 as compared to previous years?

SUMMARY ANSWER

The main trends observed in the retrospective data collections 2013–2015, representing valuable data on PGT activity in (mainly) Europe, are the increased application of trophectoderm biopsy at the cost of cleavage stage biopsy and the continuing expansion of comprehensive testing technology in PGT for chromosomal structural rearrangements and for aneuploidies (PGT-SR and PGT-A).

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting data from international PGT centres. To date, 15 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

Collection of (mainly) European data by the PGT Consortium for ESHRE. The data for PGT cycles performed between 1 January 2013 and 31 December 2015 were provided by participating centres on a voluntary basis. For the collection of cycle, pregnancy and baby data, separate, pre-designed MS Excel tables were used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 59, 60 and 59 centres respectively for 2013, 2014 and 2015 (full PGT Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XVI/XVII/XVIII, 59/60/59 centres reported data on 8164/9769/11 120 cycles with oocyte retrieval: 5020/6278/7155 cycles for PGT-A, 2026/2243/2661 cycles for PGT for monogenic/single gene defects, 1039/1189/1231 cycles for PGT-SR and 79/59/73 cycles for sexing for X-linked diseases. From 2013 until 2015, the uptake of biopsy at the blastocyst stage was mainly observed in cycles for PGT-A (from 23% to 36%) and PGT-SR (from 22% to 36%), alongside the increased application of comprehensive testing technology (from 66% to 75% in PGT-A and from 36% to 58% in PGT-SR).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 59/60/59 participating centres and may not represent worldwide trends in PGT. Data were collected retrospectively and no details of the follow-up on PGT pregnancies and babies born were provided.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT worldwide, detailed information about ongoing developments in the field is provided.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Ante-natal counseling in phacomatoses

OBJECTIVES

Phacomatoses are a group of neuro-oculo-cutaneous syndromes/ neurocutaneous disorders, involving structures arising from the embryonic ectoderm. Most of phacomatoses including the most common ones:, neurofibromatosis type I and type II (NF1, NF2) and tuberosclerosis complex (TSC), are autosomal dominant genetic disorders with full penetrance and variable expression. As no effective treatment exists, the only way to prevent the disease, is by prenatal genetic diagnosis (either chorionic villus sampling-CVS or amniocentesis-AC) and termination of pregnancy or performing preimplantation genetic testing (PGT). As the risk for an affected offspring is 50% in every pregnancy of an affected parent, prenatal, and preimplantation testing are of great importance. However, those procedures are associated with technical and ethical concerns. This chapter shortly reviews the common phacomatoses emphasizes their genetics and inheritance. We will review the common methods for prenatal and preimplantation diagnoses and discuss its use in common phacomatoses.

CONCLUSION

Phacomatoses are common autosomal dominant genetic conditions with variable expression. Ante-natal genetic diagnosis is an appropriate approach for family planning in individuals affected by phacomatosis or parents of an affected child.

Is Day-4 morula biopsy a feasible alternative for preimplantation genetic testing?

Objective

To assess the efficacy and clinical outcome of PGT-M undertaken on Day-3, Day-4 and Day-4 “delayed” embryos that were unsuitable for biopsy on Day-3.

Design and setting

Cohort-historical study of all consecutive patients admitted to the IVF-PGT-M program in a large tertiary center.

Main outcome measure(s)

The pregnancy rates and the percentages of complete, incomplete diagnosis, PCR failure, abnormal embryos in PGT of Day-3 cleavage-stage, Day-4 and Day-4 “delayed” embryos.

Patients and methods

We reviewed the medical files of all consecutive patients admitted to our IVF for a fresh IVF-PGT-M cycle. Patients were divided into 3 groups according to the day of blastomere biopsy: Day 3 cleavage-stage, Day-4 morula and Day-4 “delayed” embryos. The laboratory data, genetic diagnostic and clinical results were collected and compared between the different study groups.

Results

Nine hundred and six patients underwent PGT-M cycles in our PGT program: 747, 127 and 32 in the Day-3, Day- 4 and Day-4 “delayed” groups, respectively. Ongoing pregnancy rates per transfer and per patient (15.8% and 9.4%, respectively) were non-significantly lower in the Day-4 “delayed”, compared to Day-3 (21.4% and 17.5%, respectively) and Day-4 (24.3% and 19.7%, respectively). When comparing ALL morulas (Day-4 and Day-4 “delayed”) to ALL cleavage-stage embryos (Day-3, Day-4 and Day-4 “delayed”), a significantly higher ongoing pregnancy rate was demonstrated following the transfer of embryos derived from morula biopsy, as compared to biopsy at the cleavage-stage (33.3% vs 20.5%, p<0.03, respectively).

Conclusion

Day-4 embryo biopsy is feasible and yields comparable and even higher ongoing pregnancy rate if undertaken at the morula stage. Further studies evaluating the cumulative live-birth rate per started cycles in Day-3 vs Day-4 embryo biopsy for PGT-M are warranted.

Preimplantation genetic testing for aneuploidies (abnormal number of chromosomes) in in vitro fertilisation

BACKGROUND

In in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI), selection of the most competent embryo(s) for transfer is based on morphological criteria. However, many women do not achieve a pregnancy even after 'good quality' embryo transfer. One of the presumed causes is that such morphologically normal embryos have an abnormal number of chromosomes (aneuploidies). Preimplantation genetic testing for aneuploidies (PGT-A), formerly known as preimplantation genetic screening (PGS), was therefore developed as an alternative method to select embryos for transfer in IVF. In PGT-A, the polar body or one or a few cells of the embryo are obtained by biopsy and tested. Only polar bodies and embryos that show a normal number of chromosomes are transferred. The first generation of PGT-A, using cleavage-stage biopsy and fluorescence in situ hybridisation (FISH) for the genetic analysis, was demonstrated to be ineffective in improving live birth rates. Since then, new PGT-A methodologies have been developed that perform the biopsy procedure at other stages of development and use different methods for genetic analysis. Whether or not PGT-A improves IVF outcomes and is beneficial to patients has remained controversial.

OBJECTIVES

To evaluate the effectiveness and safety of PGT-A in women undergoing an IVF treatment.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers in September 2019 and checked the references of appropriate papers.

SELECTION CRITERIA

All randomised controlled trials (RCTs) reporting data on clinical outcomes in participants undergoing IVF with PGT-A versus IVF without PGT-A were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed risk of bias, and extracted study data. The primary outcome was the cumulative live birth rate (cLBR). Secondary outcomes were live birth rate (LBR) after the first embryo transfer, miscarriage rate, ongoing pregnancy rate, clinical pregnancy rate, multiple pregnancy rate, proportion of women reaching an embryo transfer, and mean number of embryos per transfer.

MAIN RESULTS

We included 13 trials involving 2794 women. The quality of the evidence ranged from low to moderate. The main limitations were imprecision, inconsistency, and risk of publication bias. IVF with PGT-A versus IVF without PGT-A with the use of genome-wide analyses Polar body biopsy One trial used polar body biopsy with array comparative genomic hybridisation (aCGH). It is uncertain whether the addition of PGT-A by polar body biopsy increases the cLBR compared to IVF without PGT-A (odds ratio (OR) 1.05, 95% confidence interval (CI) 0.66 to 1.66, 1 RCT, N = 396, low-quality evidence). The evidence suggests that for the observed cLBR of 24% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 17% and 34%. It is uncertain whether the LBR after the first embryo transfer improves with PGT-A by polar body biopsy (OR 1.10, 95% CI 0.68 to 1.79, 1 RCT, N = 396, low-quality evidence). PGT-A with polar body biopsy may reduce miscarriage rate (OR 0.45, 95% CI 0.23 to 0.88, 1 RCT, N = 396, low-quality evidence). No data on ongoing pregnancy rate were available. The effect of PGT-A by polar body biopsy on improving clinical pregnancy rate is uncertain (OR 0.77, 95% CI 0.50 to 1.16, 1 RCT, N = 396, low-quality evidence). Blastocyst stage biopsy One trial used blastocyst stage biopsy with next-generation sequencing. It is uncertain whether IVF with the addition of PGT-A by blastocyst stage biopsy increases cLBR compared to IVF without PGT-A, since no data were available. It is uncertain if LBR after the first embryo transfer improves with PGT-A with blastocyst stage biopsy (OR 0.93, 95% CI 0.69 to 1.27, 1 RCT, N = 661, low-quality evidence). It is uncertain whether PGT-A with blastocyst stage biopsy reduces miscarriage rate (OR 0.89, 95% CI 0.52 to 1.54, 1 RCT, N = 661, low-quality evidence). No data on ongoing pregnancy rate or clinical pregnancy rate were available. IVF with PGT-A versus IVF without PGT-A with the use of FISH for the genetic analysis Eleven trials were included in this comparison. It is uncertain whether IVF with addition of PGT-A increases cLBR (OR 0.59, 95% CI 0.35 to 1.01, 1 RCT, N = 408, low-quality evidence). The evidence suggests that for the observed average cLBR of 29% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 12% and 29%. PGT-A performed with FISH probably reduces live births after the first transfer compared to the control group (OR 0.62, 95% CI 0.43 to 0.91, 10 RCTs, N = 1680, I² = 54%, moderate-quality evidence). The evidence suggests that for the observed average LBR per first transfer of 31% in the control group, the chance of live birth after the first embryo transfer with PGT-A is between 16% and 29%. There is probably little or no difference in miscarriage rate between PGT-A and the control group (OR 1.03, 95%, CI 0.75 to 1.41; 10 RCTs, N = 1680, I² = 16%; moderate-quality evidence). The addition of PGT-A may reduce ongoing pregnancy rate (OR 0.68, 95% CI 0.51 to 0.90, 5 RCTs, N = 1121, I² = 60%, low-quality evidence) and probably reduces clinical pregnancies (OR 0.60, 95% CI 0.45 to 0.81, 5 RCTs, N = 1131; I² = 0%, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient good-quality evidence of a difference in cumulative live birth rate, live birth rate after the first embryo transfer, or miscarriage rate between IVF with and IVF without PGT-A as currently performed. No data were available on ongoing pregnancy rates. The effect of PGT-A on clinical pregnancy rate is uncertain. Women need to be aware that it is uncertain whether PGT-A with the use of genome-wide analyses is an effective addition to IVF, especially in view of the invasiveness and costs involved in PGT-A. PGT-A using FISH for the genetic analysis is probably harmful. The currently available evidence is insufficient to support PGT-A in routine clinical practice.

Reproductive decision-making in the context of hereditary cancer: the effects of an online decision aid on informed decision-making

Individuals having a genetic predisposition to cancer and their partners face challenging decisions regarding their wish to have children. This study aimed to determine the effects of an online decision aid to support couples in making an informed decision regarding their reproductive options. A nationwide pretest-posttest study was conducted in the Netherlands among 131 participants between November 2016 and May 2018. Couples were eligible for participation if one partner had a pathogenic variant predisposing for an autosomal dominant hereditary cancer syndrome. Participants completed a questionnaire before use (T0), and at 3 months (T3) after use of the decision aid to assess the primary outcome measure informed decision-making, and the secondary outcome measures decisional conflict, knowledge, realistic expectations, level of deliberation, and decision self-efficacy. T0-T3 comparisons show an overall positive effect for all outcome measures (all ps < 0.05; knowledge (ES = - 1.05), decisional conflict (ES = 0.99), participants' decision self-efficacy (ES = -0.55), level of deliberation (ES = - 0.50), and realistic expectations (ES = - 0.44). Informed decision-making increased over time and 58.0% of the participants made an informed reproductive decision at T3. The online decision aid seems to be an appropriate tool to complement standard reproductive counseling to support our target group in making an informed reproductive decision. Use of the decision aid may lessen the negative psychological impact of decision-making on couples' daily life and wellbeing.