Genetics of infertility: a paradigm shift for medically assisted reproduction

The field of reproductive genetics has undergone significant advancements with the completion of the Human Genome Project and the development of high-throughput sequencing techniques. This has led to the identification of numerous genes involved in both male and female infertility, revolutionizing the diagnosis and management of infertility patients. Genetic investigations, including karyotyping, specific genetic tests, and high-throughput sequencing, have become essential in determining the genetic causes of infertility. Moreover, the integration of genetics into reproductive medicine has expanded the scope of care to include not only affected individuals or couples but also their family members. Genetic consultations and counselling play a crucial role in identifying potentially affected relatives and offering tailored therapy and the possibility of fertility preservation. Despite the current limited therapeutic options, an increasing understanding of genotype-phenotype correlations in infertility genes holds promise for improved treatment outcomes. The availability of genetic diagnostic tools has reduced the number of idiopathic infertility cases by providing accurate aetiological diagnoses. The transition from research to clinical practice in reproductive genetics requires the establishment of genetic consultations and data warehousing systems to provide up-to-date information on gene-disease relationships. Overall, the integration of genetics into reproductive medicine has brought about a paradigm shift, emphasizing the familial dimension of infertility and offering new possibilities for personalized care and family planning.

Cleavage-stage or blastocyst-stage embryo biopsy has no impact on growth and health in children up to 2 years of age

BACKGROUND

Studies show conflicting results on neonatal outcomes following embryo biopsy for PGT, primarily due to small sample sizes and/or heterogeneity in the timing of embryo biopsy (day 3; EBD3 or day 5/6; EBD5) and type of embryo transfer. Even fewer data exist on the impact on children's health beyond the neonatal period. This study aimed to explore outcomes in children born after EBD3 or EBD5 followed by fresh (FRESH) or frozen-thawed embryo transfer (FET).

METHODS

This single-centre cohort study compared birth data of 630 children after EBD3, of 222 EBD5 and of 1532 after non-biopsied embryo transfers performed between 2014 and 2018. Follow-up data on growth were available for 426, 131 and 662 children, respectively.

RESULTS

Embryo biopsy, either at EBD3 or EBD5 in FET and FRESH cycles did not negatively affect anthropometry at birth, infancy or childhood compared to outcomes in non-biopsied FET and FRESH cycles. While there was no adverse effect of the timing of embryo biopsy (EBD3 versus EBD5), children born after EBD3 followed by FET had larger sizes at birth, but not thereafter, than children born after EBD3 followed by FRESH. Reassuringly, weight and height gain, proportions of major congenital malformations, developmental problems, hospital admissions and surgical interventions were similar between comparison groups.

CONCLUSION

Our study indicated that neither EBD3 nor EBD5 followed by FRESH or FET had a negative impact on anthropometry and on health outcomes up to 2 years of age.

A systematic review and evidence assessment of monogenic gene-disease relationships in human female infertility and differences in sex development

BACKGROUND

As in other domains of medicine, high-throughput sequencing methods have led to the identification of an ever-increasing number of gene variants in the fields of both male and female infertility. The increasing number of recently identified genes allows an accurate diagnosis for previously idiopathic cases of female infertility and more appropriate patient care. However, robust evidence of the gene-disease relationships (GDR) allowing the proper translation to clinical application is still missing in many cases.

OBJECTIVE AND RATIONALE

An evidence-based curation of currently identified genes involved in female infertility and differences in sex development (DSD) would significantly improve both diagnostic performance and genetic research. We therefore performed a systematic review to summarize current knowledge and assess the available GDR.

SEARCH METHODS

PRISMA guidelines were applied to curate all available information from PubMed and Web of Science on genetics of human female infertility and DSD leading to infertility, from 1 January 1988 to 1 November 2021. The reviewed pathologies include non-syndromic as well as syndromic female infertility, and endocrine and reproductive system disorders. The evidence that an identified phenotype is caused by pathogenic variants in a specific gene was assessed according to a standardized scoring system. A final score (no evidence, limited, moderate, strong, or definitive) was assigned to every GDR.

OUTCOMES

A total of 45 271 publications were identified and screened for inclusion of which 1078 were selected for gene and variant extraction. We have identified 395 genes and validated 466 GDRs covering all reported monogenic causes of female infertility and DSD. Furthermore, we present a genetic diagnostic flowchart including 105 genes with at least moderate evidence for female infertility and suggest recommendations for future research. The study did not take into account associated genetic risk factor(s) or oligogenic/polygenic causes of female infertility.

WIDER IMPLICATIONS

We have comprehensively reviewed the existing research on the genetics of female infertility and DSD, which will enable the development of diagnostic panels using validated genes. Whole genome analysis is shifting from predominantly research to clinical application, increasing its diagnostic potential. These new diagnostic possibilities will not only decrease the number of idiopathic cases but will also render genetic counselling more effective for infertile patients and their families.

O-021 Levothyroxine in Euthyroid Thyroid Peroxidase Antibody positive Women with Recurrent Pregnancy Loss: a multicentre, randomised, double-blind trial (T4LIFE trial)

Study question

Does levothyroxine treatment increase live birth rates in thyroid peroxidase antibodies (TPO-Ab) positive women with recurrent pregnancy loss (RPL) and normal thyroid function?

Summary answer

Levothyroxine treatment did not result in higher live birth rates in women with RPL positive for TPO-Ab and a normal thyroid function, compared to placebo.

What is known already

Women positive for TPO-Ab have a higher risk of RPL. Levothyroxine supplementation has been proposed to reduce the risk of pregnancy complications. Evidence is limited whether levothyroxine treatment improves pregnancy outcomes in TPO-Ab positive women with RPL.

Study design, size, duration

We conducted an international double-blind trial. Between January 2013 and September 2019, we randomly assigned 187 women to receive levothyroxine (94 women) or placebo (93 women). Before conception, women were randomly assigned in a 1:1 ratio to levothyroxine or placebo orally once daily. The daily dose of levothyroxine was based on preconception TSH concentration and ranged from 0.5 to 1.0 µg/kg bodyweight. Levothyroxine or placebo was continued until the end of pregnancy.

Participants/materials, setting, methods

Patients with two or more pregnancy losses underwent diagnostic testing for RPL. Women with a normal TSH level and positive for TPO-Ab were eligible for the study. Antiphospholipid syndrome was an exclusion criterion. The primary outcome was live birth, defined as the birth of a living child beyond 24 weeks of gestation. Secondary outcomes included ongoing pregnancy, pregnancy loss, preterm delivery, adverse events and time to conception leading to live birth.

Main results and the role of chance

Live birth occurred in 47 women (50%) in the levothyroxine group and in 45 women (48%) in the placebo group (risk ratio, 1.03; 95% confidence interval [CI], 0.77 to 1.38; absolute risk difference 1.6%; 95% CI, -12.7% to 15.9%). There were no significant differences in any secondary outcomes. In both groups seven adverse events were reported, none of them directly related to the study procedure.

Limitations, reasons for caution

The slow recruitment forced us to stop the trial prematurely. With this sample size we are not able to fully account for dropouts and the estimates have wide 95% confidence intervals. Detection of a difference of 5% in live birth rate would have required inclusion of more than 3000 women.

Wider implications of the findings

Routine use of levothyroxine in women with RPL and normal thyroid function positive for TPO-Ab is not recommended. Our results are in line with previous trials in TPO-Ab positive women with a history of infertility or pregnancy loss or undergoing in vitro fertilization.

Trial registration number

Netherlands Trial Register (NTR3364).

Levothyroxine in euthyroid thyroid peroxidase antibody positive women with recurrent pregnancy loss (T4LIFE trial): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Women positive for thyroid peroxidase antibodies (TPO-Ab) have a higher risk of recurrent pregnancy loss. Evidence on whether levothyroxine treatment improves pregnancy outcomes in women who are TPO-Ab positive women with recurrent pregnancy loss is scarce. The aim of this study was to determine if levothyroxine increases live birth rates in women who were TPO-Ab positive with recurrent pregnancy loss and normal thyroid function.

METHODS

The T4LIFE trial was an international, double-blind, placebo-controlled, phase 3 study done in 13 secondary and tertiary hospitals in the Netherlands, one tertiary hospital in Belgium, and one tertiary hospital in Denmark. Women (18-42 years) who were TPO-Ab positive, had two or more pregnancy losses, and had a thyroid stimulating hormone (TSH) concentration within the institutional reference range were eligible for inclusion. Women were excluded if they had antiphospholipid syndrome (lupus anticoagulant, anticardiolipin IgG or IgM antibodies, or β2-glycoprotein-I IgG or IgM antibodies), other autoimmune diseases, thyroid disease, previous enrolment in this trial, or contraindications for levothyroxine use. Before conception, women were randomly assigned (1:1) to receive either levothyroxine or placebo orally once daily. The daily dose of levothyroxine was based on preconception TSH concentration and ranged from 0·5-1·0 μg/kg bodyweight. Levothyroxine or placebo was continued until the end of pregnancy. The primary outcome was live birth, defined as the birth of a living child beyond 24 weeks of gestation measured in the intention-to-treat population. The trial was registered within the Netherlands Trial Register, NTR3364 and with EudraCT, 2011-001820-39.

RESULTS

Between Jan 1, 2013, and Sept 19, 2019, 187 women were included in the study: 94 (50%) were assigned to the levothyroxine group and 93 (50%) were assigned to the placebo group. The trial was prematurely stopped when 187 (78%) of the 240 predefined patients had been included because of slow recruitment. 47 (50%) women in the levothyroxine group and 45 (48%) women in the placebo group had live births (risk ratio 1·03 [95% CI 0·77 to 1·38]; absolute risk difference 1·6% [95% CI -12·7 to 15·9]). Seven (7%) women in the levothyroxine group and seven (8%) in the placebo group reported adverse events, none of them were directly related to the study procedure.

INTERPRETATION

Compared with placebo, levothyroxine treatment did not result in higher live birth rates in euthyroid women with recurrent pregnancy loss who were positive for TPO-Ab. On the basis of our findings, we do not advise routine use of levothyroxine in women who are TPO-Ab positive with recurrent pregnancy loss and normal thyroid function.

FUNDING

Dutch Organization for Health Research and Development, Fonds NutsOhra, Dutch Patient Organization of Thyroid Disorders, the Jan Dekkerstichting and Dr Ludgardine Bouwmanstichting, and a personal donation through the Dutch Patient Organization of Thyroid Disorders.

First live birth after fertility preservation using vitrification of oocytes in a woman with mosaic Turner syndrome

PURPOSE

To report the case of a young woman diagnosed with Turner syndrome (TS) who achieved a live birth using her own oocytes that had been vitrified for fertility preservation.

METHODS

A 25-year-old woman with mosaic (45,X/46,XX) TS was referred for fertility preservation (FP) counseling. Serum anti-Müllerian hormone (AMH) level was normal (6.4 µg/L). In view of the unpredictable rate of follicle loss in TS individuals, she requested FP and underwent two cycles of ovarian stimulation (OS) for oocyte cryopreservation (OoC) using a GnRH antagonist protocol and recombinant follicle stimulating hormone (rFSH), 200-250 IU daily for 8 resp. 12 days.

RESULTS

In total, 29 metaphase II oocytes (MII) were vitrified after OS. After conceiving spontaneously and achieving a live birth, she returned to the clinic five years after OoC with a desire for pregnancy using in vitro fertilization (IVF) of her cryopreserved oocytes and preimplantation genetic testing (PGT-A). All 29 MII oocytes were thawed; 23 oocytes survived (79.3%) and were inseminated with partner sperm using intracytoplasmic sperm injection (ICSI). Thirteen oocytes were fertilized resulting in three good quality blastocysts which were vitrified after trophectoderm biopsy for PGT-A using array-CGH. Two blastocysts were found to be euploid. One was thawed and transferred to the uterus using a HRT priming protocol. An uneventful pregnancy occurred. The patient delivered a healthy baby girl weighing 3490 g at 40 weeks of gestation.

CONCLUSIONS

We report the first live birth achieved using cryopreserved oocytes in a woman diagnosed with mosaic TS. Cryopreservation of oocytes after ovarian stimulation is a realistic option for FP in selected post menarche individuals with mosaic TS. Whether PGT-A may reduce the risk of pregnancy loss in TS has to be confirmed by further studies.

PREIMPLANTATION GENETIC TESTING: Clinical experience of preimplantation genetic testing

Thirty years of rapid technological advances in the field of genetic testing and assisted reproduction have reshaped the procedure of preimplantation genetic testing (PGT). The development of whole genome amplification and genome-wide testing tools together with the implementation of optimal hormonal stimulation protocols and more efficient cryopreservation methods have led to more accurate diagnoses and improved clinical outcomes. In addition, the shift towards embryo biopsy at day 5/6 has changed the timeline of a typical PGT clinical procedure. In this paper, we present an up-to-date overview of the different steps in PGT from patient referral to baby follow-up.

P–462 First live birth after fertility preservation using vitrified oocytes in a woman with mosaic Turner syndrome

Study question

Is oocyte vitrification an option for preserving the fertility of women diagnosed with Turner syndrome (TS)?

Summary answer

We report the first live birth achieved using cryopreserved oocytes in a woman diagnosed with mosaic Turner syndrome.

What is known already

Women with TS are at extremely high risk for premature ovarian insufficiency (POI) and infertility. Although the desire of becoming parents may be fulfilled through egg donation or adoption, fertility preservation using ovarian tissue cryopreservation or oocyte vitrification has been offered to adolescents with TS before complete exhaustion of their follicular stockpile. However, women with TS exhibit higher rates of pregnancy loss and obstetric complications, and the feasibility of fertility preservation in TS is hampered by the reduced follicular pool and by concerns about the X chromosomal content of oocytes and follicular cells.

Study design, size, duration

Case report in a university hospital.

Participants/materials, setting, methods

A 25-year-old woman with Turner syndrome mosaicism (45,X0[14]/46,XX[86]) was referred for fertility preservation (FP) counseling. Serum antimüllerian hormone (AMH) level was normal (6.4 µg/L). In view of parenthood postponement and because of the unpredictable rate of follicle loss, the woman underwent two cycles of ovarian stimulation using recombinant follicle stimulating hormone (rFSH), 200–250 IU/day for 8 resp. 12 days, in a GnRH antagonist protocol.

Main results and the role of chance

In total, 29 metaphase II oocytes (MII) were vitrified. Five years later, the patient returned to the clinic with a desire for pregnancy. Because of evidence of considerable AMH decline (–56% in an interval of four years), the patient was advised to utilize her cryopreserved oocytes for in-vitro fertilization with preimplantation genetic testing for aneuploidy screening (PGT-A). All 29 MII oocytes were thawed; 26 oocytes survived (89.7%) and were inseminated using intracytoplasmic sperm injection (ICSI). Thirteen oocytes were fertilized normally. Three good quality blastocysts ensued and were vitrified after trophectoderm biopsy for PGT-A using array-CGH. Two blastocysts were found euploid. One was thawed and transferred into the uterus using a HRT priming protocol. An uneventful pregnancy occurred. The patient delivered a healthy baby girl weighing 3490 g at 40 weeks of gestation.

Limitations, reasons for caution

Cryopreservation of oocytes and/or ovarian tissue in selected postmenarchal girls or young women with Turner syndrome is an investigational FP approach that may result in genetic parenthood. The feasibility of FP in TS individuals is limited to those with evidence of ovarian function, before POI occurs.

Wider implications of the findings: Cryopreservation of mature oocytes after ovarian stimulation is a realistic option for FP in selected postmenarchal individuals with mosaic TS. Whether PGT-A may reduce the risk of pregnancy loss in TS has to be confirmed by further studies.

Trial registration number

Not applicable

Parameters of poor prognosis in preimplantation genetic testing for monogenic disorders

STUDY QUESTION

What is the likelihood of success of a single cycle of preimplantation genetic testing for monogenic disorders (PGT-M), measured as the cumulative live birth rate (CLBR) and based on various patient demographics?

SUMMARY ANSWER

For all women aged ≤40 years, the CLBR was at least 10% when the number of oocytes was ≥7 (range 10-30%) or was at least 5% when the number of oocytes was ≥3 (range 5-17%).

WHAT IS KNOWN ALREADY

The number of oocytes is significantly associated with the number of embryos for genetic testing and the clinical outcome in PGT-M. Embryos diagnosed as affected or embryos that remain without diagnosis cannot be used for embryo transfer. The size of the group of embryos non-suitable for transfer varies between 25% and 81%, depending on the indication. Thus, PGT-M is more likely to be more severely impacted by suboptimal ovarian response, poor fertilization and suboptimal embryo development than conventional IVF/ICSI schemes without PGT.

STUDY DESIGN, SIZE, DURATION

This was a single-centre retrospective comparative cohort study, of cycles between January 2011 and December 2015. A total number of 2265 PGT-M cycles were compared to 2833 conventional ICSI cycles. The principal aim of our study was the identification of the parameters of poor CLBR in couples undergoing PGT-M using multiplex short tandem repeat (STR) markers on blastomere biopsy DNA. The secondary aim was to compare the parameters of poor CLBR of the PGT-M population to those of couples undergoing ICSI without PGT.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The baseline characteristics of the PGT-M group were compared to the conventional ICSI group. A multiple regression analysis was applied to account for the following potential confounding factors: female age, number of previous ART cycles, number of oocytes/suitable embryos for transfer and dosage of gonadotrophins used for ovarian stimulation.

MAIN RESULTS AND THE ROLE OF CHANCE

The PGT-M group was younger (female age 32.0 vs 34.5 years), had a higher number of previous ART cycles (1.1 vs 0.9 cycles) and used more gonadotrophins (2367 vs 1984 IU). Per cycle, the PGT-M group had more retrieved oocytes (11.8 vs 8.3 oocytes), fewer suitable embryos for transfer (1.7 vs 2.8 embryos) and a lower CLBR (29.4% vs 35.0%). Multiple regression analysis showed that the CLBR in the PGT-M group was significantly influenced by female age, the number of previous ART cycles, the number of oocytes and the dose of ovarian stimulation. In both groups, the predicted CLBR increased with increasing numbers of oocytes and suitable embryos. At least two retrieved oocytes or one embryo per single PGT-M cycle could confer an estimated CLBR above 10%. By assessing female age and the number of retrieved oocytes together, it was shown that for all women aged ≤40 years, the predicted CLBR per single PGT-M cycle was ≥10% when the number of oocytes was ≥7 or was ≥5% when the number of oocytes was ≥3.

LIMITATIONS, REASONS FOR CAUTION

Despite the large sample size, the findings are confined by limited confounder adjustment and the lack of specific PGT-M comparators.

WIDER IMPLICATIONS OF THE FINDINGS

This study aimed to describe the likelihood of success of PGT-M treatment, measured as CLBR, based on various patient demographics. In a PGT-M program, couples need to be informed of the prognosis more specifically when it is futile. The table of predicted CLBRs presented in this study is a useful tool in counselling PGT-M couples for making reproductive choices.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was required and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The proliferative phase endometrium in IVF/ICSI: an in-cycle molecular analysis predictive of the outcome following fresh embryo transfer

STUDY QUESTION

Does an early proliferative phase endometrial biopsy harvested during ovarian stimulation harbour information predictive of the outcome following fresh embryo transfer (ET) in that same cycle?

SUMMARY ANSWER

Transcriptome analysis of the whole-tissue endometrium did not reveal significant differential gene expression (DGE) in relation to the outcome; however, the secretome profile of isolated, cultured and in vitro decidualized endometrial stromal cells (EnSCs) varied significantly between patients who had a live birth compared to those with an implantation failure following fresh ET in the same cycle as the biopsy.

WHAT IS KNOWN ALREADY

In the majority of endometrial receptivity research protocols, biopsies are harvested during the window of implantation (WOI). This, however, precludes ET in that same cycle, which is preferable as the endometrium has been shown to adapt over time. Endometrial biopsies taken during ovarian stimulation have been reported not to harm the chances of implantation, and in such biopsies DGE has been observed between women who achieve pregnancy versus those who do not. The impact of the endometrial proliferative phase on human embryo implantation remains unclear, but deserves further attention, especially since in luteal phase endometrial biopsies, a transcriptional signature predictive for repeated implantation failure has been associated with reduced cell proliferation, possibly indicating proliferative phase involvement. Isolation, culture and in vitro decidualization (IVD) of EnSCs is a frequently applied basic research technique to assess endometrial functioning, and a disordered EnSC secretome has previously been linked with failed implantation.

STUDY DESIGN, SIZE, DURATION

This study was nested in a randomized controlled trial (RCT) investigating the effect of endometrial scratching during the early follicular phase of ovarian stimulation on clinical pregnancy rates after IVF/ICSI. Of the 96 endometrial biopsies available, after eliminating those without fresh ET and after extensive matching in order to minimize the risk of potential confounding, 18 samples were retained to study two clinical groups: nine biopsies of patients with a live birth versus nine biopsies of patients with an implantation failure, both following fresh ET performed in the same cycle as the biopsy. We studied the proliferative endometrium by analysing its transcriptome and by isolating, culturing and decidualizing EnSCs in vitro. We applied this latter technique for the first time on proliferative endometrial biopsies obtained during ovarian stimulation for in-cycle outcome prediction, in an attempt to overcome inter-cycle variability.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RNA-sequencing was performed for 18 individual whole-tissue endometrial biopsies on an Illumina HiSeq1500 machine. DGE was analysed three times using different approaches (DESeq2, EdgeR and the Wilcoxon rank-sum test, all in R). EnSC isolation and IVD was performed (for 2 and 4 days) for a subset of nine samples, after which media from undifferentiated and decidualized cultures were harvested, stored at -80°C and later assayed for 45 cytokines using a multiplex suspension bead immunoassay. The analysis was performed by partial least squares regression modelling.

MAIN RESULTS AND THE ROLE OF CHANCE

After correction for multiple hypothesis testing, DGE analysis revealed no significant differences between endometrial samples from patients who had a live birth and those with an implantation failure following fresh ET. However secretome analysis after EnSC isolation and culture, showed two distinct clusters that clearly corresponded to the two clinical groups. Upon IVD, the secretome profiles shifted from that of undifferentiated cells but the difference between the two clinical groups remained yet were muted, suggesting convergence of cytokine profiles after decidualization.

LIMITATIONS, REASONS FOR CAUTION

Caution is warranted due to the limited sample size of the study and the in vitro nature of the EnSC experiment. Validation on a larger scale is necessary, however, hard to fulfil given the very limited availability of in-cycle proliferative endometrial biopsies outside a RCT setting.

WIDER IMPLICATIONS OF THE FINDINGS

These data support the hypothesis that the endometrium should be assessed not only during the WOI and that certain endometrial dysfunctionalities can probably be detected early in a cycle by making use of the proliferative phase. This insight opens new horizons for the development of endometrial tests, whether diagnostic or predictive of IVF/ICSI treatment outcome.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Fonds Wetenschappelijk Onderzoek (FWO, Flanders, Belgium, 11M9415N, 1 524 417N), Wetenschappelijk Fonds Willy Gepts (WFWG G160, Universitair Ziekenhuis Brussel, Belgium) and the National Medicine Research Council (NMRC/CG/M003/2017, Singapore). There are no conflicts of interests.

TRIAL REGISTRATION NUMBER

NCT02061228.

Multiple vitrification-warming and biopsy procedures on human embryos: clinical outcome and neonatal follow-up of children

STUDY QUESTION

Does double vitrification and warming of human blastocysts having undergone biopsy once or twice have an impact on the clinical outcome?

SUMMARY ANSWER

The clinical pregnancy rate obtained with double vitrification single biopsy blastocysts was comparable to that obtained with single vitrification single biopsy blastocysts in our center in the same time period (46%; 2016-2018), whereas that obtained with double-vitrified double-biopsied blastocysts seemed lower and will need further study.

WHAT IS KNOWN ALREADY

Genetic testing on cryopreserved unbiopsied embryos involves two cryopreservation procedures. Retesting of failed/inconclusive-diagnosed blastocysts inevitably involves a second round of biopsy and a second round of vitrification as well. To what extent this practice impacts on the developmental potential of blastocysts has been studied to a limited extent so far and holds controversy. Additionally, the obstetrical/perinatal outcome after the transfer of double-vitrified/single or double-biopsied blastocysts is poorly documented.

STUDY DESIGN, SIZE, DURATION

This retrospective observational study included 97 cycles of trophectoderm biopsy and preimplantation genetic testing (PGT) on vitrified-warmed embryos followed by a second round of vitrification between March 2015 and December 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In 36 warming cycles, no biopsy was performed on the embryos before the first vitrification (single biopsy group). In 61 warming cycles, the embryos had been biopsied on Day 3 (n = 4) or on Day 5/6 (n = 57) before the first vitrification (double biopsy group). A second biopsy was mostly indicated in cycles of failed or inconclusive diagnosis at the first biopsy. Two cycles involved a more specific mutation test for X-linked diseases on male embryos and one cycle involved testing for a second monogenic indication supplementary to a previously tested reciprocal translocation. Post-warming suitability for biopsy, availability of genetically transferable embryos and clinical outcome of subsequent frozen-thawed embryo transfer (FET) cycles were reported. Neonatal follow-up of the children was included.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 91 cleavage-stage embryos and 154 blastocysts were warmed, of which 34 (37.4%) and 126 (81.8%), respectively, were of sufficient quality to undergo trophectoderm biopsy and were subsequently vitrified for a second time. Out of these, 92 underwent biopsy for the first time (single biopsy), whereas 68 underwent a second biopsy (double biopsy). After diagnosis, 77 blastocysts (48.1%) were revealed to be genetically transferable (44 in the single biopsy group and 33 in the double biopsy group). In 46 warming cycles, 51 blastocysts were warmed and 49 survived this second warming procedure (96.0%). Subsequently, there were 45 FET cycles resulting in 27 biochemical pregnancies and 18 clinical pregnancies with fetal heartbeat (40.0% per FET cycle: 44.0% in the single biopsy group and 35.0% in the double biopsy group, P = 0.54). Thirteen singletons were born (eight in the single biopsy group and five in the double biopsy group), while three pregnancies were ongoing. A total of 26 embryos (13 in each group) remain vitrified and have the potential to increase the final clinical pregnancy rate. The neonatal follow-up of the children born so far is reassuring.

LIMITATIONS, REASONS FOR CAUTION

This is a small retrospective cohort, thus, the implantation potential of double vitrification double biopsy blastocysts, as compared to double vitrification single biopsy blastocysts and standard PGT (single vitrification, single biopsy), certainly needs further investigation. Although one could speculate on birthweight being affected by the number of biopsies performed, the numbers in this study are too small to compare birthweight standard deviation scores in singletons born after single or double biopsy.

WIDER IMPLICATIONS OF THE FINDINGS

PGT on vitrified-warmed embryos, including a second vitrification-warming step, results in healthy live birth deliveries, for both single- and double-biopsied embryos. The neonatal follow-up of the 13 children born so far did not indicate any adverse effect. The present study is important in order to provide proper counseling to couples on their chance of a live birth per initial warming cycle planned and concerning the safety issue of rebiopsy and double vitrification.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Factors influencing the clinical outcome of preimplantation genetic testing for polycystic kidney disease

STUDY QUESTION

What are the factors influencing the success rate for couples undergoing preimplantation genetic testing (PGT) for polycystic kidney disease (PKD)?

SUMMARY ANSWER

In our study cohort, the live birth delivery rate is significantly associated with female age while the male infertility accompanying autosomal dominant PKD (ADPKD) does not substantially affect the clinical outcome.

WHAT IS KNOWN ALREADY

While women with ADPKD have no specific fertility problems, male ADPKD patients may present with reproductive system abnormalities and infertility.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study involves 91 PGT cycles for PKD for 43 couples (33 couples for PKD1, 2 couples for PKD2 and 8 couples for autosomal recessive PKD (ARPKD)) from January 2005 until December 2016 with follow-up of transfers until end of 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sixteen single-cell clinical tests for PKD based on multiplex PCR of short tandem repeat markers, with or without a specific mutation were developed and applied for diagnosis of 584 Day 3 cleavage stage embryos. In 18 couples, the male partner was affected with ADPKD (=Group A) and 12 of them had a documented infertility status. Group A underwent 52 cycles to oocyte retrieval. For 18 other couples, the female partner was affected with ADPKD (=Group B) and four male partners from this group had a documented history of infertility. This group underwent 31 cycles to OR.

MAIN RESULTS AND THE ROLE OF CHANCE

Genetic analysis resulted in 545 embryos (93.3%) with a diagnosis, of which 215 (36.8%) were genetically transferable. Transfer of 74 embryos in 53 fresh cycles and of 34 cryopreserved embryos in 33 frozen-warmed embryo transfer cycles resulted in a live birth delivery rate of 38.4% per transfer with 31 singleton live births, two twin live births and one ongoing pregnancy. The observed cumulative delivery rate was 57.8% per couple after five treatment cycles. Thirty cryopreserved embryos still remain available for transfer. The clinical pregnancy rate per transfer (fresh + frozen; 45.9% in group A versus 60.0% in group B, P < 0.05) and the live birth delivery rate per transfer (fresh + frozen; 27.0% in group A versus 42.9% in group B, P < 0.05) was significantly lower for couples with the male partner affected with ADPKD compared with couples with the female partner affected with ADPKD. However, a multivariate logistic regression analysis showed that only female age was associated with live birth delivery rate (odds ratio = 0.87; 95% CI: 0.77-0.99; P = 0.032).

LIMITATIONS, REASONS FOR CAUTION

This study is based on retrospective data from a single centre with Day 3 one-cell and two-cell biopsy. Further analysis of a larger cohort of PKD patients undergoing PGT is required to determine the impact of male infertility associated with ADPKD on the cumulative results.

WIDER IMPLICATIONS OF THE FINDINGS

Knowledge about factors affecting the clinical outcome after PGT can be a valuable tool for physicians to counsel PKD patients about their reproductive options. Males affected with ADPKD who suffer from infertility should be advised to seek treatment in time to improve their chances of conceiving a child.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was obtained. There are no competing interests to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Preimplantation genetic testing with HLA matching: from counseling to birth and beyond

Preimplantation genetic testing-human leukocyte antigen '(PGT-HLA) only' refers to the HLA typing of single or few cells biopsied from in vitro fertilized preimplantation embryos. The aim of the procedure is to establish a pregnancy, in which the fetus is HLA compatible with an affected sibling in need of a hematopoietic stem cell transplantation (HSCT). During PGT-M-HLA, the identification of a HLA-compatible embryo is combined with the detection of mutation(s) underlying immunodeficiencies and hemoglobinopathies. We report a combined retrospective and prospective cohort analysis of PGT-(M-)HLA procedures carried out from 1998 until 2017, with follow-up of transplantations to 2019. During the study period, 234 couples from 22 countries were invited for a multidisciplinary consultation. Two couples were rejected and 70 couples declined (various reasons), leaving 162 couples for which 414 clinical cycles were carried out. Cleavage stage biopsy followed by single-cell multiplex PCR for short tandem repeat-based haplotyping was applied in most cases (98.7%). The diagnostic efficiency was high (94.8%) but only 16.5% of the embryos was genetically suitable for transfer. Fresh and frozen-thawed embryo transfer resulted in 67 clinical pregnancies, 63 deliveries, and 74 live births, of which 60 children were HLA compatible. This yielded a live birth delivery rate of 30.3% per transfer. Information on neonatal characteristics of the matching PGT-(M-)HLA children showed reassuring outcomes. So far, HSCT was carried out successfully for 25 out of 26 cases. In conclusion, our data show that PGT-(M-)HLA is a valuable procedure: the high complexity and limited delivery rate are balanced by the successful HSCT outcome and the positive impact on families.

Preimplantation genetic testing for aneuploidy by microarray analysis of polar bodies in advanced maternal age: a randomized clinical trial

STUDY QUESTION

Does preimplantation genetic testing for aneuploidy (PGT-A) by comprehensive chromosome screening (CCS) of the first and second polar body to select embryos for transfer increase the likelihood of a live birth within 1 year in advanced maternal age women aged 36-40 years planning an ICSI cycle, compared to ICSI without chromosome analysis?

SUMMARY ANSWER

PGT-A by CCS in the first and second polar body to select euploid embryos for transfer does not substantially increase the live birth rate in women aged 36-40 years.

WHAT IS KNOWN ALREADY

PGT-A has been used widely to select embryos for transfer in ICSI treatment, with the aim of improving treatment effectiveness. Whether PGT-A improves ICSI outcomes and is beneficial to the patients has remained controversial.

STUDY DESIGN, SIZE, DURATION

This is a multinational, multicentre, pragmatic, randomized clinical trial with intention-to-treat analysis. Of 396 women enroled between June 2012 and December 2016, 205 were allocated to CCS of the first and second polar body (study group) as part of their ICSI treatment cycle and 191 were allocated to ICSI treatment without chromosome screening (control group). Block randomization was performed stratified for centre and age group. Participants and clinicians were blinded at the time of enrolment until the day after intervention.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Infertile couples in which the female partner was 36-40 years old and who were scheduled to undergo ICSI treatment were eligible. In those assigned to PGT-A, array comparative genomic hybridization (aCGH) analysis of the first and second polar bodies of the fertilized oocytes was performed using the 24sure array of Illumina. If in the first treatment cycle all oocytes were aneuploid, a second treatment with PB array CGH was offered. Participants in the control arm were planned for ICSI without PGT-A. Main exclusion criteria were three or more previous unsuccessful IVF or ICSI cycles, three or more clinical miscarriages, poor response or low ovarian reserve. The primary outcome was the cumulative live birth rate after fresh or frozen embryo transfer recorded over 1 year after the start of the intervention.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 205 participants in the chromosome screening group, 50 (24%) had a live birth with intervention within 1 year, compared to 45 of the 191 in the group without intervention (24%), a difference of 0.83% (95% CI: -7.60 to 9.18%). There were significantly fewer participants in the chromosome screening group with a transfer (relative risk (RR) = 0.81; 95% CI: 0.74-0.89) and fewer with a miscarriage (RR = 0.48; 95% CI: 0.26-0.90).

LIMITATIONS, REASONS FOR CAUTION

The targeted sample size was not reached because of suboptimal recruitment; however, the included sample allowed a 90% power to detect the targeted increase. Cumulative outcome data were limited to 1 year. Only 11 patients out of 32 with exclusively aneuploid results underwent a second treatment cycle in the chromosome screening group.

WIDER IMPLICATIONS OF THE FINDINGS

The observation that the similarity in birth rates was achieved with fewer transfers, less cryopreservation and fewer miscarriages points to a clinical benefit of PGT-A, and this form of embryo selection may, therefore, be considered to minimize the number of interventions while producing comparable outcomes. Whether these benefits outweigh drawbacks such as the cost for the patient, the higher workload for the IVF lab and the potential effect on the children born after prolonged culture and/or cryopreservation remains to be shown.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the European Society of Human Reproduction and Embryology. Illumina provided microarrays and other consumables necessary for aCGH testing of polar bodies. M.B.'s institution (UZBrussel) has received educational grants from IBSA, Ferring, Organon, Schering-Plough, Merck and Merck Belgium. M.B. has received consultancy and speakers' fees from Organon, Serono Symposia and Merck. G.G. has received personal fees and non-financial support from MSD, Ferring, Merck-Serono, Finox, TEVA, IBSA, Glycotope, Abbott and Gedeon-Richter as well as personal fees from VitroLife, NMC Healthcare, ReprodWissen, BioSilu and ZIVA. W.V., C.S., P.M.B., V.G., G.A., M.D., T.E.G., L.G., G.Ka., G.Ko., J.L., M.C.M., M.P., A.S., M.T., K.V., J.G. and K.S. declare no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT01532284.

TRIAL REGISTRATION DATE

7 February 2012.

DATE OF FIRST PATIENT’S ENROLMENT

25 June 2012.

Genetic diagnosis of subfertility: the impact of meiosis and maternal effects

During reproductive age, approximately one in seven couples are confronted with fertility problems. While the aetiology is diverse, including infections, metabolic diseases, hormonal imbalances and iatrogenic effects, it is becoming increasingly clear that genetic factors have a significant contribution. Due to the complex nature of infertility that often hints at a multifactorial cause, the search for potentially causal gene mutations in idiopathic infertile couples has remained difficult. Idiopathic infertility patients with a suspicion of an underlying genetic cause can be expected to have mutations in genes that do not readily affect general health but are only essential in certain processes connected to fertility. In this review, we specifically focus on genes involved in meiosis and maternal-effect processes, which are of critical importance for reproduction and initial embryonic development. We give an overview of genes that have already been linked to infertility in human, as well as good candidates which have been described in other organisms. Finally, we propose a phenotypic range in which we expect an optimal diagnostic yield of a meiotic/maternal-effect gene panel.

Is genetic fatherhood within reach for all azoospermic Klinefelter men?

Background

Multidisciplinary management of Klinefelter cases is now considered good clinical practice in order to ensure optimal quality of life. Reproductive performance of Klinefelter men is an important issue however literature in this domain is limited and prone to bias.

Study design

This was a retrospective longitudinal cohort study performed at a tertiary referral University Centre for Reproductive Medicine and Genetics. One hundred thirty-eight non-mosaic azoospermic Klinefelter patients undergoing their first testicular biopsy (TESE) between 1994 and 2013, followed by intracytoplasmic sperm injection (ICSI) with fresh or frozen-thawed testicular sperm in the female partner, were followed-up longitudinally. The main outcome measure was cumulative live birth rate per Klinefelter patient embarking on TESE-ICSI.

Findings

In forty-eight men (48/138) sperm were successfully retrieved at the first TESE (34.8%). The mean age of the patients was 32.4 years. Younger age at first TESE was associated with a higher sperm retrieval rate (p<0.001). Overall 39 couples underwent 62 ICSI cycles and 13 frozen embryo transfer cycles resulting in in 20 pregnancies and 14 live birth deliveries (16 children). The mean age of the female partner was 28.1 years. The crude cumulative delivery rate after four ICSI cycles was 35.9%. Per intention-to-treat however, only 10.1% (14/138) of the Klinefelter men starting treatment succeeded in having their biologically own child(ren).

Conclusion

Non-mosaic Klinefelter patients with azoospermia seeking treatment by TESE-ICSI should be counseled that by intention-to-treat the chance of retrieving sperm is fair, however only a minority will eventually father genetically own children.

BRCA1 mutation carriers have a lower number of mature oocytes after ovarian stimulation for IVF/PGD

Purpose

The aim of this study was to determine whether BRCA1/2 mutation carriers produce fewer mature oocytes after ovarian stimulation for in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD), in comparison to a PGD control group.

Methods

A retrospective, international, multicenter cohort study was performed on data of first PGD cycles performed between January 2006 and September 2015. Data were extracted from medical files. The study was performed in one PGD center and three affiliated IVF centers in the Netherlands and one PGD center in Belgium. Exposed couples underwent PGD because of a pathogenic BRCA1/2 mutation, controls for other monogenic conditions. Only couples treated in a long gonadotropin-releasing hormone (GnRH) agonist-suppressive protocol, stimulated with at least 150 IU follicle stimulating hormone (FSH), were included. Women suspected to have a diminished ovarian reserve status due to chemotherapy, auto-immune disorders, or genetic conditions (other than BRCA1/2 mutations) were excluded. A total of 106 BRCA1/2 mutation carriers underwent PGD in this period, of which 43 (20 BRCA1 and 23 BRCA2 mutation carriers) met the inclusion criteria. They were compared to 174 controls selected by frequency matching.

Results

Thirty-eight BRCA1/2 mutation carriers (18 BRCA1 and 20 BRCA2 mutation carriers) and 154 controls proceeded to oocyte pickup. The median number of mature oocytes was 7.0 (interquartile range (IQR) 4.0–9.0) in the BRCA group as a whole, 6.5 (IQR 4.0–8.0) in BRCA1 mutation carriers, 7.5 (IQR 5.5–9.0) in BRCA2 mutation carriers, and 8.0 (IQR 6.0–11.0) in controls. Multiple linear regression analysis with the number of mature oocytes as a dependent variable and adjustment for treatment center, female age, female body mass index (BMI), type of gonadotropin used, and the total dose of gonadotropins administered revealed a significantly lower yield of mature oocytes in the BRCA group as compared to controls (p = 0.04). This finding could be fully accounted for by the BRCA1 subgroup (BRCA1 mutation carriers versus controls p = 0.02, BRCA2 mutation carriers versus controls p = 0.50).

Conclusions

Ovarian response to stimulation, expressed as the number of mature oocytes, was reduced in BRCA1 but not in BRCA2 mutation carriers. Although oocyte yield was in correspondence to a normal response in all subgroups, this finding points to a possible negative influence of the BRCA1 gene on ovarian reserve.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-017-1014-3) contains supplementary material, which is available to authorized users.

The why, the how and the when of PGS 2.0: current practices and expert opinions of fertility specialists, molecular biologists, and embryologists

STUDY QUESTION

We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0?

STUDY FINDING

Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS.

WHAT IS KNOWN ALREADY

It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst stage is currently called into question.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

A questionnaire was developed on the three major aspects of PGS 2.0: the Why, with general questions such as PGS 2.0 indications; the How, specifically on genetic analysis methods; the When, on the ideal method and timing of embryo biopsy. Thirty-five colleagues have been selected to address these questions on the basis of their experience with PGS, and demonstrated by peer-reviewed publications, presentations at meetings and participation in the discussion. The first group of experts who were asked about 'The Why' comprised fertility experts, the second group of molecular biologists were asked about 'The How' and the third group of embryologists were asked about 'The When'. Furthermore, the geographical distribution of the experts has been taken into account. Thirty have filled in the questionnaire as well as actively participated in the redaction of the current paper.

MAIN RESULTS AND THE ROLE OF CHANCE

The 30 participants were from Europe (Belgium, Germany, Greece, Italy, Netherlands, Spain, UK) and the USA. Array comparative genome hybridization is the most widely used method amongst the participants, but it is slowly being replaced by massive parallel sequencing. Most participants offering PGS 2.0 to their patients prefer blastocyst biopsy. The high efficiency of vitrification of blastocysts has added a layer of complexity to the discussion, and it is not clear whether PGS in combination with vitrification, PGS alone, or vitrification alone, followed by serial thawing and eSET will be the favoured approach. The opinions range from in favour of the introduction of PGS 2.0 for all IVF patients, over the proposal to use PGS as a tool to rank embryos according to their implantation potential, to scepticism towards PGS pending a positive outcome of robust, reliable and large-scale RCTs in distinct patient groups.

LIMITATIONS, REASONS FOR CAUTION

Care was taken to obtain a wide spectrum of views from carefully chosen experts. However, not all invited experts agreed to participate, which explains a lack of geographical coverage in some areas, for example China. This paper is a collation of current practices and opinions, and it was outside the scope of this study to bring a scientific, once-and-for-all solution to the ongoing debate.

WIDER IMPLICATIONS OF THE FINDINGS

This paper is unique in that it brings together opinions on PGS 2.0 from all different perspectives and gives an overview of currently applied technologies as well as potential future developments. It will be a useful reference for fertility specialists with an expertise outside reproductive genetics.

LARGE SCALE DATA

none.

STUDY FUNDING AND COMPETING INTERESTS

No specific funding was obtained to conduct this questionnaire.

Live birth rates following natural cycle IVF in women with poor ovarian response according to the Bologna criteria

STUDY QUESTION

What is the effect of natural cycle IVF in women with poor ovarian response according to the new ESHRE definition for poor ovarian responders: the Bologna criteria?

SUMMARY ANSWER

Although natural cycle IVF is a promising treatment option for normal responders, poor ovarian responders, as described by the Bologna criteria, have a very poor prognosis and do not appear to experience substantial benefits with natural cycle IVF.

WHAT IS KNOWN ALREADY

Previous trials have shown that natural cycle IVF is an effective treatment for the general infertile population and might be an option for poor ovarian responders. However, none of the trials have examined the effect of natural cycle IVF in poor responders according to the Bologna criteria, the newly introduced definition by the ESHRE Working Group on Poor Ovarian Response Definition. In this trial, we examined the effect of natural cycle IVF in poor ovarian responders fulfilling the Bologna criteria.

STUDY DESIGN, SIZE, DURATION

In this retrospective cohort trial, 164 consecutive patients, undergoing 469 natural cycle IVFs between 2008 and 2011 were included. Patients were stratified as poor and normal responders: 136 (390 cycles) were poor ovarian responders according to the Bologna criteria, whereas 28 women (79 treatment cycles) did not fulfil the criteria and were considered as normal responders.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All patients were monitored with hormonal analysis and ultrasound scan every second day, from Day 7 or 8 of the cycle onwards. When a follicle of >16 mm was observed, ovulation was triggered with 5000 IU of i.m. hCG and oocyte retrieval was performed 32 h later.

MAIN RESULTS AND THE ROLE OF CHANCE

Live birth rates in poor responders according to the Bologna criteria were significantly lower compared with the control group of women; the live birth rate per cycle was 2.6 versus 8.9%, P = 0.006 and the live birth rate per treated patient was 7.4 versus 25%, P = 0.005. In poor responders according to the Bologna criteria, live birth rates were consistently low and did not differ among different age groups (≤ 35 years, 36-39 years and ≥ 40 years), with a range from 6.8 to 7.9%.

LIMITATIONS, REASONS FOR CAUTION

A limitation of our analysis is its retrospective design; however, taking into account that we included only consecutive patients treated with exactly the same protocol, the likelihood of selection bias might be considerably limited. In addition, the control group in our study refers to women of younger age and therefore the promising results among patients who did not fulfil the Bologna criteria apply only to women of younger age.

WIDER IMPLICATIONS OF THE FINDINGS

Our trial suggests that although natural cycle IVF is a promising treatment option for younger normal responders, its potential is very limited to poor ovarian responders as described by the Bologna criteria, irrespective of patient's age. This highlights the very poor prognosis of these women and therefore the urgent need for future trials to examine the effect of ovarian stimulation protocols in women with poor ovarian response as described by the Bologna criteria.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was used. There are no competing interests to declare.

Preimplantation genetic diagnosis in female and male carriers of reciprocal translocations: clinical outcome until delivery of 312 cycles

Carriers of reciprocal translocations (rcp) are known to be at risk for reproductive difficulties. Preimplantation genetic diagnosis (PGD) is one of the options these carriers have to try in order to fulfil their desire to have a child. In the present study, we retrospectively looked at the results of 11 years (1997-2007) of PGD for rcp in our center to improve the reproductive counseling of these carriers. During this period 312 cycles were performed for 69 male and 73 female carriers. The mean female age was 32.8 years, the mean male age 35.8 years. Most carriers were diagnosed with a translocation because of fertility problems or recurrent miscarriages, and most of them opted for PGD to avoid these problems. In 150 of the 312 cycles, embryo transfer (ET) was feasible and 40 women had a successful singleton or twin pregnancy. This gives a live birth delivery rate of 12.8% per started cycle and of 26.7% per cycle with ET. Owing to the large number of abnormal embryos, PGD cycles for rcp often lead to cancellation of ET, explaining the low success rate when expressed per cycle with oocyte pick-up. Once ET was feasible, the live birth delivery rate was similar to that of PGD in general at our center. PGD is therefore an established option for specific reciprocal translocation carriers.

A novel method of luteal supplementation with recombinant luteinizing hormone when a gonadotropin-releasing hormone agonist is used instead of human chorionic gonadotropin for ovulation triggering: a randomized prospective proof of concept study

This pilot study investigates the role of luteal supplementation with recombinant LH in an attempt to reverse the poor reproductive outcome previously noticed after GnRH-agonist triggering of final oocyte maturation for IVF. Similar implantation rates were achieved with the novel recombinant LH luteal supplementation scheme compared with the standard luteal P protocol (25.0% vs. 26.7%, respectively). No cases of ovarian hyperstimulation syndrome (OHSS) were noticed in either group.

Impact of cleavage-stage embryo biopsy in view of PGD on human blastocyst implantation: a prospective cohort of single embryo transfers

BACKGROUND

Human embryo biopsy is performed for preimplantation genetic diagnosis (PGD). The impact of 1- or 2-cell removal at cleavage-stage on future embryo development and implantation capacity is highly debated.

METHODS

In order to explore this issue further, a cohort of Day 5 single embryo transfers was analysed prospectively for embryological and clinical outcome. All transferred embryos resulted from 8-cell embryos on Day 3, from which subsequently either one cell (group I, n = 182) or two cells (group II, n = 259) were removed, or on which no invasion by means of embryo biopsy was performed (group III, control group, n = 702). RESULTS Blastocyst formation was significantly better in group III compared with group II, and similar to group I. Group I and group II did not differ in Day 3 nor in Day 5 embryo development. The overall live birth rate was significantly higher in group I (37.4%, CI 29.0-47.4%) than in group II (22.4%, CI 17.0-28.9%), and comparable to the reference ICSI population (35.0%, CI 30.8-39.7%).

CONCLUSIONS

The clinical outcome of 1-cell biopsy was significantly better than that of 2-cell biopsy, even when adjusted for availability of genetically transferable embryos.

Report on a consecutive series of 581 children born after blastomere biopsy for preimplantation genetic diagnosis

BACKGROUND

Preimplantation genetic diagnosis (PGD) and subsequently preimplantation genetic screening (PGS) have been introduced since 1990. The difference from the already existing in vitro fertilization (IVF) technology, using intracytoplasmic sperm injection (ICSI), was the embryo biopsy at day 3 after fertilization. Although healthy children post-PGD/PGS have been born, the question of whether embryo biopsy could have any harmful effects has to be studied on large series in a prospective manner.

METHODS

A prospective cohort study was undertaken from 1992 until 2005, using the same approach as for the follow-up of IVF and ICSI children conceived in the same centre. Questionnaires were sent to physicians and parents at conception and at delivery. Children were examined at 2 months of age by trained clinical geneticists whenever possible.

RESULTS

Data collected on 581 post-PGD/PGS children showed that term, birthweight and major malformation rates were not statistically different from that of 2889 ICSI children, with overall rates of major malformation among these post-PGD/PGS and ICSI children being 2.13 and 3.38%, respectively (odds ratio [OR]: 0.62; exact 95% confidence limits [95% CL]: 0.31-1.15). However, the overall perinatal death rate was significantly higher among post-PGD/PGS children compared with ICSI children (4.64 versus 1.87%; OR: 2.56; 95% CL: 1.54-4.18). When stratified for multiple births, perinatal death rates among PGD/PGS singleton and ICSI singleton children were similar (1.03 versus 1.30%; OR: 0.83; 95% CL: 0.28-2.44), but significantly more perinatal deaths were seen in post-PGD/PGS multiple pregnancies compared with ICSI multiple pregnancies (11.73 versus 2.54%; OR: 5.09; 95% CL: 2.80-9.90). The overall misdiagnosis rate was below 1%.

CONCLUSIONS

Embryo biopsy does not add risk factors to the health of singleton children born after PGD or PGS. The perinatal death rate in multiple pregnancies is such that both caution and long-term follow-up are required.

The incidence of monozygotic twinning following PGD is not increased

BACKGROUND

Monozygotic (MZ) twin pregnancies are associated with increased perinatal mortality and morbidity, and risk of congenital anomalies. The causes of MZ twinning in humans are unclear but the incidence may increase after PGD, for example, as a result of holes created in the zona pellucida. We compared the incidence of MZ twin pregnancies in ICSI cycles with PGD, versus ICSI cycles without PGD.

METHODS

In this retrospective comparative cohort study, we analysed incidence of twin pregnancies in unselected patients undergoing ICSI and PGD (group A; 1992 cycles) with blastocyst transfer at Day 5, versus a period-matched control population of unselected patients undergoing ICSI and blastocyst transfer at Day 5 without PGD (group B; 2429 cycles) from January 2001 to December 2006.

RESULTS

Clinical pregnancy per embryo transfer was established in 618/1992 (31.0%) and 947/2429 (39.0%) in group A versus B, respectively (P < 0.01). Overall MZ twin rate was 29/4421 (0.7%) per embryo transfer and 29/1565 (1.9%) per established clinical pregnancy. The incidence of MZ twinning per established clinical pregnancy did not differ between groups (1.5 versus 2.1%, group A and B, respectively). In group A, seven MZ twins were born versus 19 MZ twins in group B. In group B, one MZ twin pregnancy resulted in two stillbirths. In group A, two MZ twins had severe congenital malformations versus none in group B.

CONCLUSIONS

The incidence of MZ twinning was not increased in PGD compared with regular ICSI with blastocyst transfer. This information is useful in counselling patients about potential risks of PGD.

ICSI: Hype or hazard?

Ever since its introduction in clinical practice more than 10 years ago, intracytoplasmic sperm injection (ICSI) has been the subject of ongoing debate regarding its indications and safety. ICSI is hyped because of its potential to give couples with severe male factor infertility a chance to conceive, and because of its apparently low fertilization failure rate compared with 'classic' in vitro fertilization (IVF). Concerns about ICSI are related to technical, biological and genetic hazards. ICSI has been branded 'the ultimate rape of the oocyte', as the oocyte membrane is mechanically pierced, appearing to bypass all biological and genetic selection. ICSI has been linked in a number of reports to an increased incidence of chromosomal anomalies, congenital abnormalities and perinatal hazards in offspring conceived with this technique. The etiology of the increased risk of chromosomal anomalies in ICSI offspring, especially sex-chromosome anomalies, is thought to be partly multifactorial, partly andrological, related to paternal karyotypic abnormalities and/or abnormal sperm. The majority of studies on ICSI and IVF offspring have, setting aside inconsistencies in methodology and classification, not shown significant differences between the two techniques in terms of congenital abnormalities, however, compared to naturally conceived offspring there does show an increased risk. This risk is attributed mainly to parental factors such as maternal age, poor sperm quality and infertility as an independent risk factor. Perinatal hazards may include low birth weight and perinatal mortality. Behavioural and psychological development is carefully monitored in ICSI and IVF children with no significant differences to the development of naturally conceived children, but many factors are involved including demographics. Follow-up studies are essential to the technique of ICSI. It is our duty to inform patients of the concerns and benefits to this treatment, based on the latest data available.

Preimplantation genetic diagnosis: design or too much design

Preimplantation genetic diagnosis (PGD) is a technique that was first applied in humans in 1990 (Handyside et al., 1990; Verlinsky et al., 1990). Thirty years on an estimated 15000 children have been conceived and born using PGD, a number dwarfed by the huge number of children already conceived via conventional in vitro fertilisation. In contrast to numerous reports on reproductive outcome in conventional IVF, data on reproductive outcome of PGD are scarse. There is ongoing debate about the diagnostic accuracy and clinical relevance of Preimplantation genetic screening for aneuploidy (PGS) (Shahine et al., 2006; Twisk et al., 2006), however well conducted prospective randomized studies are few. In this PhD summary, the author describes the reproductive results of a large PGD program and applies life table analysis with multiple regression analysis and comparative analysis where appropriate. Potential risks of PGD including misdiagnosis, perinatal mortality and monozygotic twinning rate are assessed. The aim is to provide both patients and physicians with adequate information on all reproductive aspects of PGD as a diagnostic and therapeutic tool.

Preimplantation genetic screening does not improve delivery rate in women under the age of 36 following single-embryo transfer

BACKGROUND

Single-embryo transfer is a well-accepted strategy to avoid multiple pregnancies in an assisted reproductive technology (ART) programme. Besides the morphological quality and embryo kinetics up to the blastocyst stage, preimplantation genetic screening (PGS) of aneuploidy has been advocated as an adjuvant approach to select the embryo.

METHODS

Couples with a female partner younger than 36 were randomly assigned to undergo transfer of a single blastocyst in a cycle with or without PGS using FISH for the chromosomes X, Y, 13, 16, 18, 21, 22.

RESULTS

After the enrolment of 120 of the projected 447 patients in each group, study recruitment was terminated prematurely on the basis of futility. The observed live birth delivery rates after ART were 30.8 versus 30.8% per randomized patient, 34.6 versus 34.6% per cycle initiated, 37.8 versus 37.0% per aspirated cycle and 41.6 versus 43.5% per embryo transfer for the control versus the PGS group, respectively, with absolute between-group differences (95% CI; P value) of 0% (-11.7 to 11.7; P = 1.00), 0% (-12.7 to 12.7; P = 1.00), -0.8% (-14.2 to 12.7; P = 0.91) and 2.1% (-12.7 to 16.7; P = 0.79), respectively. Even in this younger age group, only 61% of the embryos had a normal diploid status.

CONCLUSIONS

The absence of a beneficial treatment effect in this randomized clinical trial provides no arguments in favour of PGS to improve live birth delivery rate following single-embryo transfer in women under the age 36. Clinical Trials.gov: NCT00670059.