Improved clinical utility of preimplantation genetic testing through the integration of ploidy and common pathogenic microdeletions analyses

STUDY QUESTION

Can chromosomal abnormalities beyond copy-number aneuploidies (i.e. ploidy level and microdeletions (MDs)) be detected using a preimplantation genetic testing (PGT) platform?

SUMMARY ANSWER

The proposed integrated approach accurately assesses ploidy level and the most common pathogenic microdeletions causative of genomic disorders, expanding the clinical utility of PGT.

WHAT IS KNOWN ALREADY

Standard methodologies employed in preimplantation genetic testing for aneuploidy (PGT-A) identify chromosomal aneuploidies but cannot determine ploidy level nor the presence of recurrent pathogenic MDs responsible for genomic disorders. Transferring embryos carrying these abnormalities can result in miscarriage, molar pregnancy, and intellectual disabilities and developmental delay in offspring. The development of a testing strategy that integrates their assessment can resolve current limitations and add valuable information regarding the genetic constitution of embryos, which is not evaluated in PGT providing new level of clinical utility and valuable knowledge for further understanding of the genomic causes of implantation failure and early pregnancy loss. To the best of our knowledge, MDs have never been studied in preimplantation human embryos up to date.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort analysis including blastocyst biopsies collected between February 2018 and November 2021 at multiple collaborating IVF clinics from prospective parents of European ancestry below the age of 45, using autologous gametes and undergoing ICSI for all oocytes. Ploidy level determination was validated using 164 embryonic samples of known ploidy status (147 diploids, 9 triploids, and 8 haploids). Detection of nine common MD syndromes (-4p=Wolf-Hirschhorn, -8q=Langer-Giedion, -1p=1p36 deletion, -22q=DiGeorge, -5p=Cri-du-Chat, -15q=Prader-Willi/Angelman, -11q=Jacobsen, -17p=Smith-Magenis) was developed and tested using 28 positive controls and 97 negative controls. Later, the methodology was blindly applied in the analysis of: (i) 100 two pronuclei (2PN)-derived blastocysts that were previously defined as uniformly euploid by standard PGT-A; (ii) 99 euploid embryos whose transfer resulted in pregnancy loss.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The methodology is based on targeted next-generation sequencing of selected polymorphisms across the genome and enriched within critical regions of included MD syndromes. Sequencing data (i.e. allelic frequencies) were analyzed by a probabilistic model which estimated the likelihood of ploidy level and MD presence, accounting for both sequencing noise and population genetics patterns (i.e. linkage disequilibrium, LD, correlations) observed in 2504 whole-genome sequencing data from the 1000 Genome Project database. Analysis of phased parental haplotypes obtained by single-nucleotide polymorphism (SNP)-array genotyping was performed to confirm the presence of MD.

MAIN RESULTS AND THE ROLE OF CHANCE

In the analytical validation phase, this strategy showed extremely high accuracy both in ploidy classification (100%, CI: 98.1-100%) and in the identification of six out of eight MDs (99.2%, CI: 98.5-99.8%). To improve MD detection based on loss of heterozygosity (LOH), common haploblocks were analyzed based on haplotype frequency and LOH occurrence in a reference population, thus developing two further mathematical models. As a result, chr1p36 and chr4p16.3 regions were excluded from MD identification due to their poor reliability, whilst a clinical workflow which incorporated parental DNA information was developed to enhance the identification of MDs. During the clinical application phase, one case of triploidy was detected among 2PN-derived blastocysts (i) and one pathogenic MD (-22q11.21) was retrospectively identified among the biopsy specimens of transferred embryos that resulted in miscarriage (ii). For the latter case, family-based analysis revealed the same MD in different sibling embryos (n = 2/5) from non-carrier parents, suggesting the presence of germline mosaicism in the female partner. When embryos are selected for transfer based on their genetic constitution, this strategy can identify embryos with ploidy abnormalities and/or MDs beyond aneuploidies, with an estimated incidence of 1.5% (n = 3/202, 95% CI: 0.5-4.5%) among euploid embryos.

LIMITATIONS, REASONS FOR CAUTION

Epidemiological studies will be required to accurately assess the incidence of ploidy alterations and MDs in preimplantation embryos and particularly in euploid miscarriages. Despite the high accuracy of the assay developed, the use of parental DNA to support diagnostic calling can further increase the precision of the assay.

WIDER IMPLICATIONS OF THE FINDINGS

This novel assay significantly expands the clinical utility of PGT-A by integrating the most common pathogenic MDs (both de novo and inherited ones) responsible for genomic disorders, which are usually evaluated at a later stage through invasive prenatal testing. From a basic research standpoint, this approach will help to elucidate fundamental biological and clinical questions related to the genetics of implantation failure and pregnancy loss of otherwise euploid embryos.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. S.C., M.F., F.C., P.Z., I.P., L.G., C.P., M.P., D.B., J.J.-A., D.B.-J., J.M.-V., and C.R. are employees of Igenomix and C.S. is the head of the scientific board of Igenomix. A.C. and L.P. are employees of JUNO GENETICS. Igenomix and JUNO GENETICS are companies providing reproductive genetic services.

TRIAL REGISTRATION NUMBER

N/A.

P-733 Implementing preconception expanded carrier screening in a universal healthcare system: insights from a cost-effectiveness analysis

Study question

Would reimbursement of expanded carrier screening (ECS) panels of different gene content be cost-effective in a universal healthcare system?

Summary answer

Both tested ECS panels would be cost-effective if reimbursed by the Italian national healthcare system for a population without personal/familiar or racial/ethnic preconception genetic risks.

What is known already

Collectively, Mendelian diseases are a significant cause of infant mortality and hospitalization. Current preconception screening strategies test a limited number of individuals based on self-reported personal/familiar or racial/ethnic background. Consequently, the majority of at risk couples (ARCs) remain hidden in the general population. If adopted at a population level, multiplex platforms can thus improve screening effectiveness by allowing rapid ECS for a large number of conditions. Available economic evaluations assume the perspective of private/commercial payers. However, the decision to reimburse ECS in a tax-based national healthcare system would benefit from a cost-effectiveness analysis from the perspective of the public payer.

Study design, size, duration

This cost-effectiveness decision model compared lifetime costs and effects of two preconception ECS panels (i.e., “Strategy A1” (testing Cystic Fibrosis, Spinal-Muscular-Atrophy, Beta Thalassemia, Phenylketonuria and Fragile-X-Syndrome) and “Strategy A2” (testing “Strategy A1” + 16 common severe highly-penetrant childhood conditions in the Mediterranean population)) with no screening (“Strategy B”). We embraced the perspective of the Italian National Healthcare System. The time horizon for each condition equals an affected child’s life expectancy.

Participants/materials, setting, methods

We included couples seeking pregnancy without personal/familiar or racial/ethnic genetic risk. The cost-effectiveness analysis was based on a decision tree model where: i) the ECS panels sensitivity was 100%; ii) the probability for at risk couples (ARCs) to be risk-adverse was 77% based on data available from the literature; iii) all the forms of intervention that risk-adverse couples opted for lowered to zero the risk to conceive an affected child for the considered conditions.

Main results and the role of chance

Unitary cost of €240 for Strategy A1 and of €270 for Strategy A2 for each couple were estimated through a market analysis simulating a public ECS provision. For risk-adverse couples, the cost of intervention was estimated as equal to €8,376. This resulted from the weighted mean of the cost of the different options available (i.e., in vitro fertilization (IVF) with preimplantation testing for monogenic disorders (PGT-M) or, in case of natural conception, prenatal diagnosis and, eventually, termination of pregnancy). Strategy A1 was dominant versus no screening: Strategy A1 entailed savings equal to €1,395 and an incremental benefit of 0.0154 life years gained. Strategy A2 was dominant versus no screening: Strategy A2 entailed savings of €2,273 and an incremental benefit of 0.0238 life years gained. Strategy A2, when compared with Strategy A1, entailed an incremental cost of €649 and higher health benefits (0.7688 life years gained) (incremental cost-effectiveness ratio (ICER): €844).

Limitations, reasons for caution

This decision analytic model relies on input parameters on costs and life expectancy associated to each Mendelian disease derived from the literature. However, the feasibility to generate experimental evidence to inform this type of studies is very limited. The cost-effectiveness profiles established are valid under the assumptions listed.

Wider implications of the findings

Cost-effectiveness analyses like the one performed are useful policy tools to inform decisions regarding preconception screening programs for detectable severe recessive highly penetrant early-onset genetic conditions.

Trial registration number

not applicable

P-621 Different gonadotrophins adopted for controlled ovarian stimulation do not affect metaphase-II oocyte competence. A matched case-control study on 351 patients and 2258 oocytes

Study question

Do different gonadotrophins for controlled-ovarian-stimulation (COS) affect metaphase-II (MII) oocyte competence?

Summary answer

Euploid blastocyst rate (EBR) per cohort of MII-oocytes, live-birth-rate (LBR) per first vitrified-warmed euploid single-embryo-transfer (SET) and cumulative-LBR are independent from the gonadotrophins used.

What is known already

Controlled-ovarian-stimulation (COS) is a cornerstone of IVF. Its purpose is maximizing ovarian reserve exploitation and obtaining ≥1 euploid blastocyst to transfer. Indeed, ovarian reserve decreases and blastocyst aneuploidy rates increase with increasing maternal age, making this task quite complicated in advanced maternal age. Old-fashioned studies suggested an association between COS and embryonic aneuploidy rates. Conversely, recent studies excluded an impact of COS dosage, duration, ovarian response, and ovulation trigger, on blastocyst aneuploidy rate. An aspect, though, needs more clarity: do different gonadotropins impact oocyte competence after COS, comprehensively defined as EBR per cohort of MII-oocytes?

Study design, size, duration

Out of 3169 PGT cycles with ³1 MII oocyte conducted between 2014-2018, we excluded (i)PGT-M/-SR, (ii)women<35yr, (iii)severe-male-factor, (iv)DuoStim or long-active FSH, (v)culture with sequential-media, and (v)multiple cycles. Among the 784 cycles left, a propensity-score-matching (PSM) based on the number of inseminated MII-oocytes was adopted to match patients using recFSH [without (N = 57; 337 MII-oocytes)/with recLH (N = 55; 374 MII-oocytes)] and Human-Menopausal-Gonadotrophin (HMG; N = 127; 835 MII-oocytes). The patients using recFSH+HMG were all included (N = 112; 712 MII-oocytes).

Participants/materials, setting, methods

Only GnRH-antagonist COS, ICSI with fresh MII-oocytes, single culture in continuous-media, trophectoderm biopsy without assisted-hatching, comprehensive-chromosome-testing to assess full-chromosome non-mosaic aneuploidies and vitrified-warmed euploid SET were conducted. Oocyte competence was comprehensively defined as EBR per cohort of MII-oocytes with all intermediate outcomes (fertilization, blastulation and euploidy). LBR per first vitrified-warmed euploid SET and cumulative-LBR per retrieval were also assessed. Generalized-linear-models and multivariate regressions were adopted to adjust the results for confounders. All cycles were concluded.

Main results and the role of chance

Patients using recFSH+recLH and recFSH+HMG (40.7 yr) were older than patients using recFSH-only or HMG-only (40 yr; ANOVA<0.01). No other difference was reported in the 4 patient populations. The overall gonadotrophins dosage (2615±977, 3601±1889, 3818±946 and 2892±911 IU in the recFSH-only, recFSH+recLH, recFSH+HMG and HMG-only groups, respectively) and duration of COS (9.7±1.9, 9.4±1.5, 9.9±1.8 and 10.2±1.8 days) were different (Kruskal-Wallis tests=0.02). The number of cumulus-oocyte-complexes (9.2±6.5) and MII-oocytes collected (6.4±4.4) were instead well-matched across the groups. The EBR per cohort of inseminated MII-oocytes was different in the four groups (20.7±27.1%, 9.6±12.9%, 12.4±18.5% and 16.9±21.8%, respectively), but, when adjusted for maternal age in a generalized-linear-model, the gonadotrophin used for COS did not show any significant association with this outcome (partial-eta2=0.02, p = 0.1, power=0.6). All intermediate embryological outcomes were also similar. The LBR per first vitrified-warmed euploid SET was comparable in the four groups [N = 14/33 (42%), N = 9/22 (41%), N = 26/62 (45%), N = 24/55 (44%), respectively], as confirmed by the logistic regression adjusted for blastocyst quality (multivariate-OR: 0.97, 95%CI 0.73-1.31, adjusted-p=0.9). Lastly, the cumulative-LBRs per retrieval were equivalent [N = 17/57 (30%), N = 14/55 (26%), N = 34/127 (27%), and N = 33/112 (30%), respectively], as confirmed by the logistic regression adjusted for maternal age (multivariate-OR: 1.01, 95%CI 0.8-1.3, adjusted-p=0.9).

Limitations, reasons for caution

The gonadotrophins were chosen based on patient compliance to their administration route and gynecologist judgement, and only qualitative outcomes were assessed. Therefore, randomized-controlled-trials and cost-effectiveness analysis investigating the efficiency in oocyte recruitment and cumulative-LBR per intention-to-treat are needed.

Wider implications of the findings

Different gonadotrophins might not affect MII-oocyte competence. This information is key since, in view of the optimization of follicle recruitment through personalized-COS, it allows more flexibility in the choice of the most suitable protocol. Therefore, gynecologists might ponder also features like patient reproductive history and compliance to different administration routes.

Trial registration number

none

O-042 ESHRE good practice recommendations on chromosomal mosaicism

The implementation of high-resolution genome-wide methods, usually next-generation sequencing-based, in preimplantation genetic testing (PGT), has led to the frequent detection of embryos with chromosomal mosaicism (whole chromosome and/or segmental aberrations). Despite a growing series of papers showing the birth of healthy babies following the transfer of embryos indicating mosaicism on PGT-A analysis - albeit with lower implantation rates and higher miscarriage rates in comparison with euploid embryo transfer - many questions remain, making it difficult to decide on how to handle chromosomally mosaic embryos in the clinic.

A dedicated ESHRE working group developed good practice recommendations on how to manage chromosomal mosaicism in clinical practice. The recommendations were formulated based on the expert opinion of the working group while taking into consideration the published data and outcomes of a survey on current practices in 239 PGT laboratories and ART clinics, mostly within Europe, Asia and America. The recommendations with regards to detection and management of chromosomal mosaicism were developed following the manual for development of ESHRE good practice recommendations with a stakeholder review of the paper on the ESHRE website. In addition to the recommendations, the working group identified missing information and scientific questions, which should guide further research in PGT, with relevance to the occurrence, detection and impact of chromosomal mosaicism.

Trial registration number:

P-555 Improved clinical validity of Preimplantation Genetic Testing for Aneuploidy (PGT-A) using a next-generation sequencing workflow for simultaneous detection of aneuploidy, ploidy and common pathogenic microdeletions

Study question

Can chromosomal abnormalities beyond aneuploidies (i.e., ploidy and microdeletions, MD) be detected on a single trophectoderm (TE) embryo biopsy using a next-generation sequencing (NGS)-based workflow?

Summary answer

This NGS-based integrated approach allows accurate detection of ploidy status and the most common microdeletions from a single TE-biopsy,expanding PGT-A clinical validity and diagnostic capabilities.

What is known already

Standard methodologies employed in PGT-A do not determine embryo ploidy status due to the normalization process during copy-number-variation analysis. Transferring embryos with abnormal ploidy variations is expected to result in miscarriage or molar pregnancy. Common pathogenic MD are undetected as they fall below the PGT-A resolution limit (<10Mb). MD are involved in genomic disorders associated with neurodevelopmental disabilities and multiple congenital anomalies. The development of this sequencing strategy can resolve current limitations and add valuable information regarding the genetic constitution of embryos, which is not usually evaluated in PGT and normally requires the use of later-stage invasive prenatal diagnosis.

Study design, size, duration

Ploidy determination was validated using 244 embryo samples of known ploidy status (226 diploids, 10 triploids, 8 haploids). We analysed nine common MD syndromes (-4p=Wolf-Hirschhorn, -8q=Langer-Giedion, -1p=1p36 deletion, -22q=DiGeorge, -5p=Cri-du-Chat, -15q=Prader-Willi/Angelman, -11q=Jacobsen, -17p=Smith-Magenis) using 24 positive controls (amniocentesis DNA from MD cases or TE biopsies from autosomal monosomy mimicking MD) and 96 negative controls (healthy newborns). Overall, the dataset included 72 cases of individual chromosomal abnormalities and 576 negative cases across the eight MD regions.

Participants/materials, setting, methods

PGT-A products were reamplified and sequenced (IonTorrentS5-ThermoFisher) using a custom AmpliSeq panel targeting 384 regions with at least one Single Nucleotide Polymorphism (SNP) of high B-allelic frequency. A bioinformatic algorithm based on gaussian-mixture modelling of sequencing data was developed. This algorithm calculates the conditional probability of the observed B-allelic ratio for each SNP, depending on the copy number, then estimates the likelihood of ploidy and the presence of MD based on the sequencing outcomes.

Main results and the role of chance

Ploidy was correctly determined in 233/234 cases (Accuracy=99.4%), with only one diploid sample misclassified as triploid (PPV=94.1%, NPV=100%, Non-informative rate=9/243=3.1%).

Microdeletions could be consistently detected with high reliability in 6 out of the 8 considered regions (-8q,-22q,-5p,-15q,-11q and -17p; PPV=98.5%, NPV=99.5%). Detection of microdeletions of 1p and 4p were less reliable due to the presence of recurrent haplotype blocks in the population at those genomic regions, as confirmed by the analysis of a dataset of 2504 whole genome sequencing from One Thousand Genome Project database (1kGP). The only MD false positive case showed extended loss of heterozygosity in the microdeletion region (-22q), which might be related to uniparental disomy or consanguinity and requires further testing in the family.

This analytical framework was blindly applied to: (i) the analysis of 9 embryos from a family affected by DiGeorge syndrome (female partner was carrier of del22.q11.21(20754422-21440514), resulting in all embryos classified consistently with the conventional PGT-M results (using indirect linkage analysis); (ii) the analysis of samples from 99 transferred human euploid embryos resulting in pregnancy losses. No ploidy alteration was detected in miscarried euploid embryos, but 2 microdeletions (-8q, -22q) were found, with an estimated prevalence of 2/99 in the miscarriage population.

Limitations, reasons for caution

Larger cohort studies will be required to accurately assess the incidence of ploidy alterations and microdeletions in preimplantation embryos and particularly in euploid miscarriages. Despite the high accuracy of the assay developed, the use of parental DNA to support diagnostic calling can further increase the precision of the assay.

Wider implications of the findings

This study provides, for the first time, detection of common pathogenic microdeletions and ploidy status from a single TE biopsy, expanding PGT-A clinical validity. This new assay will also help elucidate fundamental biological and clinical questions related to the genetics of implantation failure and pregnancy loss of apparently euploid embryos.

Trial registration number

not applicable

O-115 Parental whole-exome sequencing allows the discovery of genetic causes of extreme IVF phenotypes such as oocyte/embryo developmental arrest and recurrent low fertilization

Study question

Do whole-exome sequencing (WES) data from infertile women provide valuable information for the discovery of genes/pathways involved in extreme IVF phenotypes, i.e. oocyte/embryo developmental arrest?

Summary answer

The development of a specific bioinformatic WES pipeline revealed known and new candidate genes/pathways for isolated oocyte/embryo developmental failure,providing the foundation to scale up research.

What is known already

The use of IVF has made it possible to identify extreme and isolated infertility phenotypes such as recurrent low oocytes maturity (LMR), recurrent low fertilization rate (LFR), or preimplantation developmental arrest (PDA) that would remain concealed in natural conception attempts. Recent applications of WES in families with such extreme adverse IVF phenotypes have led to the discovery of new genes and pathways affecting unique functions of gametes and exclusive mechanisms necessary for early embryo development. Here, we apply a tailored bioinformatic approach to WES from women displaying extreme IVF phenotypes to discover new causative genes/pathways involved in unexplained infertility.

Study design, size, duration

Twenty-two infertile consanguineous women(December 2018-September 2020) suffering from long-term unexplained infertility. Eight cases were classified as PDA (<20% normally developed embryos in > 2 IVF cycles), 8 as LMR (<20% mature oocytes in > 2 IVF cycles), 4 as LFR (<20% of normally fertilized oocytes in > 2 IVF cycles). Two women with recurrent IVF failure (>10 IVF cycles) were also included. A control set of 1660 WES from oocyte donors was used to control for false-positive discoveries.

Participants/materials, setting, methods

WES at 30X was performed on enrolled women’s gDNA using Illumina short-reads technology. Following annotation, variants were filtered to prioritize putative detrimental variants in genes relevant for oocyte/embryonic development using a previously developed and validated pipeline that minimizes false-positive discoveries. Runs of homozygosity (ROH) within each sample were identified using Refined IBD software. Individual-level single-cell RNAseq (scRNAseq) dataset from 18 human oocytes was used to verify the expression of the identified target genes.

Main results and the role of chance

The variant prioritization pipeline employed identified 1,160 unique variants in 1,017 genes (average per sample 59.9 sd 8.5). 453 variants were private to this study compared to the 1000 Genomes and gnomAD databases, 3% affecting splicing and/or the gene product length. Significant 5-fold enrichment of 41 genes involved in DNA-damage and repair pathways commonly associated with ovarian function/oocyte quality was observed (p < 0.001). TP53/AKT pathway also showed significant 5-fold enrichment for 45 genes (p < 0.001). This finding is consistent with the known relationship between infertility and cell-cycle/cancer genes. Overall, 66.4% (675/1,017; 95%CI:63.4-69.3) of the targeted genes were expressed in MII human oocytes. Two women (9%) were homozygous carriers of missense pathogenic variants in known candidate genes previously associated to oocyte/embryo developmental arrest (TRIP13, chr5_901344_C/T, CADD percentile 0.999; PADI6, chr1_17394384_C/G, CADD percentile 0.999). Remarkably, four additional women were carriers of high-impact variants in JAKMIP1, a member of a recently characterized family of proteins involved in various cellular processes, including cytoskeleton rearrangement, cell polarization, and intracellular transport. High-impact JAKMP1 variants were never observed in the oocyte donor control dataset. JAKMIP1 mRNA was detected in each individual biological replicate of scRNAseq analysis of MII oocytes with a mean of 6 transcripts per million.

Limitations, reasons for caution

Functional analysis is ongoing to validate the newly identified genes, data need to be verified in different ethnicities. Nevertheless, this study demonstrates the establishment of a specific and scalable analytical framework that can be employed for the identification of genetic causes in unexplained infertility cases characterized by defective developmental patterns.

Wider implications of the findings

Scaling up this investigative approach would provide an effective strategy for discovering new genes/pathways in what is considered idiopathic infertility, further defining precision reproductive medicine interventions. Importantly, this study revealed lesions in genetic patterns involved in chronic diseases providing a molecular footprint of the well-established link between infertility and comorbidities.

Trial registration number

none

P–530 The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos

Study question

What is the effect of varying diagnostic thresholds on the accuracy of Next Generation Sequencing (NGS)-based preimplantation genetic testing for aneuploidies (PGT-A)?

Summary answer

When single trophectoderm biopsies are tested, the employment of 80% upper threshold increases mosaic calls and false negative aneuploidy results compared to more stringent thresholds.

What is known already

Trophectoderm (TE) biopsy coupled with NGS-based PGT-A technologies are able to accurately predict Inner Cell Mass’ (ICM) constitution when uniform whole chromosome aneuploidies are considered. However, minor technical and biological inconsistencies in NGS procedures and biopsy specimens can result in subtle variability in analytical results. In this context, the stringency of thresholds employed for diagnostic calls can lead to incorrect classification of uniformly aneuploid embryos into the mosaic category, ultimately affecting PGT-A accuracy. In this study, we evaluated the diagnostic predictivity of different aneuploidy classification criteria by employing blinded analysis of chromosome copy number values (CNV) in multifocal blastocyst biopsies.

Study design, size, duration

The accuracy of different aneuploidy diagnostic cut-offs was assessed comparing chromosomal CNV in intra-blastocysts multifocal biopsies. Enrolled embryos were donated for research between June and September 2020. The Institutional Review Board at the Near East University approved the study (project: YDU/20l9/70–849). Embryos diagnosed with uniform chromosomal alterations (single or multiple) in their clinical TE biopsy (n = 27) were disaggregated into 5 portions: the ICM and 4 TE biopsies. Overall, 135 specimens were collected and analysed.

Participants/materials, setting, methods

Twenty-seven donated blastocysts were warmed and disaggregated in TE biopsies and ICM (n = 135 biopsies). PGT-A analysis was performed using Ion ReproSeq PGS kit and Ion S5 sequencer (ThermoFisher). Sequencing data were blindly analysed with Ion-Reporter software. Intra-blastocyst comparison of raw NGS data was performed employing different thresholds commonly used for aneuploidy classification. CNV for each chromosome were reported as aneuploid according to 70% or 80% thresholds. Categorical variables were compared using Fisher’s exact test.

Main results and the role of chance

In this study, a total of 50 aneuploid patterns in 27 disaggregated embryos were explored. Single TE biopsy results were considered as true positive when they displayed the same alteration detected in the ICM at levels above the 70% or 80% thresholds. Alternatively, alterations detected in the euploid or mosaic range were considered as false negative aneuploidy results. When the 70% threshold was applied, aneuploidy findings were confirmed in 94.5% of TE biopsies analyzed (n = 189/200; 95%CI=90.37–37.22), while 5.5% showed a mosaic profile (50–70%) but uniformly abnormal ICM. Positive (PPV) and negative predictive value (NPV) per chromosome were 100.0% (n = 189/189; 95%CI=98.07–100.00) and 99.5% (n = 2192/2203; 95%CI=99.11–99.75) respectively. When the upper cut-off was experimentally placed at 80% of abnormal cells, a significant decrease (p-value=0.0097) in the percentage of confirmed aneuploid calls was observed (86.5%; n = 173/200; 95%CI=80.97–90.91), resulting in mosaicism overcalling, especially in the high range (50–80%). Less stringent thresholds led to extremely high PPV (100.0%; n = 173/173; 95%CI=97.89–100.00), while NPV decreased to 98.8% (n = 2192/2219; 95%CI=98.30–99.23). Furthermore, no additional true mosaic patterns were identified with the use of wide range thresholds for aneuploidy classification.

Limitations, reasons for caution

This approach involved the analysis of aneuploidy CNV thresholds at the embryo level and lacked from genotyping-based confirmation analysis. Moreover, aneuploid embryos with known meiotic partial deletion/duplication were not included.

Wider implications of the findings: The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos, lowering overall diagnostic accuracy. Hence, a proportion of the embryos diagnosed as mosaic using wide calling thresholds may actually be uniformly aneuploid and inadvertently transferred.

Trial registration number

N/A

P–500 Euploid embryo-transfer reduces advanced maternal age patients’ anxiety in the waiting period before the pregnancy-test

Study question

Can PGT-A reduce the anxiety generally experienced by infertile women undergoing IVF in the waiting period between embryo transfer and the pregnancy test?

Summary answer

PGT-A reduces anxiety in infertile women after embryo transfer, probably due to a gain of confidence in their treatment route.

What is known already

The waiting period, i.e. the time between embryo-transfer and the pregnancy-test, is considered unpredictable and unmanageable, thus figuring amongst the most stressful steps of an IVF treatment. This is mainly imputable to women’s lost sense of control over the outcome. Uncertainty is in fact a source of fear and elevated distress. PGT-A has been shown to improve live birth rate per embryo transfer and reduce miscarriage rate per clinical pregnancy across several trials and observational studies worldwide, especially in advanced maternal age (AMA) women. Here, we investigated if euploid embryo transfer does involve also lower emotional burden over untested one.

Study design, size, duration

Prospective observational study evaluating the level of anxiety in the waiting period among women undergoing euploid or untested embryo transfer. Data were collected between September 2019 and September 2020 in a public hospital. A total of 48 infertile women were recruited: 25 undergoing euploid single embryo transfer after trophectoderm biopsy and NGS, and 23 undergoing untested single embryo transfer.

Participants/materials, setting, methods

To measure the level of anxiety, the two groups completed the STAI (State Trait Anxiety Inventory) questionnaire at two time points: before starting the ovarian stimulation (T0), and at day 8 after embryo transfer (T1). The chosen questionnaire has been previously validated to capture the level of patients’ anxiety during the waiting period. Outcomes of T0 were used to control for individual level state of anxiety at T1.

Main results and the role of chance

The two groups showed similar reproductive history and sociodemographic characteristics except for female age, which was higher in the PGT-A group (37.7±3.2 yr versus 32.3±2.2 yr in the control). This is due to AMA (maternal age >35 yr) being the main indication to PGT-A. Conversely, the duration of infertility was similar in the two groups (3.8±2.2 yr versus 3.7±1.9 in the control). At T0 all patients showed similar levels of anxiety (46.4 points versus 49.9 in the control, 95%CI of the difference: from –9.97 to 3.03 points, p = 0.3). Remarkably, at T1 instead, the women undergoing euploid embryo transfer showed a significantly decreased level of anxiety with respect to the control (39.9 points versus 53.4; 95% CI of the difference: from –18.26 to –8.69, p < 0.01). This difference remained significant also after controlling for the baseline value at T0, and adjusting for potential confounding factors in a multivariate analysis (adjusted p-value<0.01).

Limitations, reasons for caution

The sample size is small, yet the study resulted powered enough to reveal the considerable advantage of PGT-A toward the primary outcome. We analysed only the waiting period here. Therefore, data will be collected in the future at subsequent gestational stages, such as when prenatal genetic diagnosis is usually conducted.

Wider implications of the findings: Women undergoing PGT-A seem reassured by the technique. This is probably due to the gain of confidence and control derived from an increased expectation of success. From this perspective, assessing women’s wellbeing and attitude towards all different clinical procedures should become a critical part of their treatment.

Trial registration number

None

P-536 Pre-selected for an award: Validation of a Next Generation Sequencing (NGS) workflow integrating simultaneous analysis of ploidy, microdeletions and de novo monogenic diseases for expanded preimplantation genetic testing (PGT)

Study question

Can major de novo genetic and chromosomal abnormalities (i.e., ploidy, microdeletions) be effectively tested on a single embryo biopsy specimen using an integrated NGS approach?

Summary answer

The integrated NGS workflow provided high accuracy for multilevel chromosome and genetic abnormalities analysis based on single biopsies expanding PGT informativity to de novo conditions.

What is known already

Current NGS-based methodologies employed in PGT for aneuploidy (PGT-A) do not detect embryo ploidy level nor frequent pathogenic de novo microdeletions below resolution limits. Moreover, despite their considerable incidence and adverse pregnancy outcomes, de novo mutations causing severe dominant monogenic fetal structural defects (FSD) are not investigated during PGT. The development of a single biopsy specimen-based PGT-A sequencing strategy that integrates ploidy and de novo microdeletions/mutations assessment would significantly widen PGT-A diagnostic scope and technical capabilities. This comprehensive approach would provide additional valuable genetic information of unquestionable clinical utility to further refine embryo selection process among those showing euploid profiles.

Study design, size, duration

Chromosomal conditions were validated using 24 embryo rebiopsies and 5 cell lines with both known ploidy level and known microdeletions (-4p; -8q; -1p; -22q; -5p; -15q; -11q). Genotyping for monogenic conditions was validated using 5 genomic DNA samples (33pg/µl) carrying known pathogenic Single Nucleotide Variants (SNVs) in COL1A1, SOS1, PTPN11, TSC2 and FGFR2 genes. To assess technical performance across identified SNPs, genotyping accuracy was evaluated on 17 samples from 5 embryos and 2 cell lines.

Participants/materials, setting, methods

Thirty-two de novo dominant monogenic conditions with FSD and strong gene-disease relationship were tested using a multiplex PCR panel with sequencing for the genes’ whole coding region. Eight common microdeletions ( < 10Mb) syndromes (Wolf-Hirshorn, Langer-Geidion, 1p36 deletion, De George, Cri-du-Chat, Prader-Willy/Angelman, Jacobsen) were tested using B-allelic frequency (BAF) of 356 highly polymorphic Single Nucleotide Polymorphisms (SNPs). These SNPs were also used for ploidy assessment. Library preparation and sequencing were performed on the IonTorrent S5 (ThermoFisher).

Main results and the role of chance

Blinded NGS data analysis confirmed the ploidy status in all (19) samples with known constitution (8 diploids, 7 polyploids, 4 haploids). Specifically, the proportion of heterozygote calls (BAF 40%-60%) was 60.9% (95%CI:47.6-72.8) for diploid samples and < 1% for haploid samples(P < 0.001). All polyploid samples showed a typical splitting of BAF among 3 experimental ranges (20-40%,40%-60%,60-80%): 34.1%,18.2% and 47.7%, respectively. For microdeletions, all interstitial SNPs genotyped showed a loss of heterozygosity (LOH) as expected. The analysis of positive controls consisting of 20 blastocyst rebiopsies and 3 cell lines (-4p: n = 3; -8q: n = 4; -1p: n = 5; -22q: n = 3; -5p: n = 2; -15q: n = 4; -11q: n = 2), allowed to accurately characterize 6 out of the 7 microdeletions (18/23 samples). In particular, all interstitial SNPs genotyped showed a LOH, while diploid controls showed an overall heterozygosity of 30.9% (average number of hetSNP x deletion = 9/28). Only the very small telomeric 1p36 region failed to properly amplify. For monogenic conditions, sequencing analysis of 5 positive gDNA controls confirmed the presence of 4 known SNVs, whilst only 1 did not achieve the minimum coverage for variant calling. Moreover, 4 additional de novo SNVs detected by sequencing analysis in the gene panel on 8 blastocyst rebiopsies were all confirmed by qPCR/Taqman assays.

Limitations, reasons for caution

Positive controls were not available for all genes and microdeletions included in the panel. Moreover, inefficient amplification has affected some target regions and further optimization will be required. However, analytical performance on technical and biological replicates were highly promising for the tested conditions both cell lines and trophectoderm biopsies.

Wider implications of the findings

This study demonstrates that the integration of genotyping and chromosomal analyses can be efficiently achieved in the same NGS workflow. This approach can be employed to expand PGT diagnostic scope to conditions undetectable in parents due to their de novo onset, or that are below the standard PGT-A resolution.

Trial registration number

N/A

P–536 Validation of a Next Generation Sequencing (NGS) workflow integrating simultaneous analysis of ploidy, microdeletions and de novo monogenic diseases for expanded preimplantation genetic testing (PGT)

Study question

Can major de novo genetic and chromosomal abnormalities (i.e., ploidy, microdeletions) be effectively tested on a single embryo biopsy specimen using an integrated NGS approach?

Summary answer

The integrated NGS workflow provided high accuracy for multilevel chromosome and genetic abnormalities analysis based on single biopsies expanding PGT informativity to de novo conditions.

What is known already

Current NGS-based methodologies employed in PGT for aneuploidy (PGT-A) do not detect embryo ploidy level nor frequent pathogenic de novo microdeletions below resolution limits. Moreover, despite their considerable incidence and adverse pregnancy outcomes, de novo mutations causing severe dominant monogenic fetal structural defects (FSD) are not investigated during PGT. The development of a single biopsy specimen-based PGT-A sequencing strategy that integrates ploidy and de novo microdeletions/mutations assessment would significantly widen PGT-A diagnostic scope and technical capabilities. This comprehensive approach would provide additional valuable genetic information of unquestionable clinical utility to further refine embryo selection process among those showing euploid profiles.

Study design, size, duration

Chromosomal conditions were validated using 24 embryo rebiopsies and 5 cell lines with both known ploidy level and known microdeletions (–4p; –8q; –1p; –22q; –5p; –15q; –11q). Genotyping for monogenic conditions was validated using 5 genomic DNA samples (33pg/µl) carrying known pathogenic Single Nucleotide Variants (SNVs) in COL1A1, SOS1, PTPN11, TSC2 and FGFR2 genes. To assess technical performance across identified SNPs, genotyping accuracy was evaluated on 17 samples from 5 embryos and 2 cell lines.

Participants/materials, setting, methods

Thirty-two de novo dominant monogenic conditions with FSD and strong gene-disease relationship were tested using a multiplex PCR panel with sequencing for the genes’ whole coding region. Eight common microdeletions (<10Mb) syndromes (Wolf-Hirshorn, Langer-Geidion, 1p36 deletion, De George, Cri-du-Chat, Prader-Willy/Angelman, Jacobsen) were tested using B-allelic frequency (BAF) of 356 highly polymorphic Single Nucleotide Polymorphisms (SNPs). These SNPs were also used for ploidy assessment. Library preparation and sequencing were performed on the IonTorrent S5 (ThermoFisher).

Main results and the role of chance

Blinded NGS data analysis confirmed the ploidy status in all (19) samples with known constitution (8 diploids, 7 polyploids, 4 haploids). Specifically, the proportion of heterozygote calls (BAF 40%–60%) was 60.9% (95%CI:47.6–72.8) for diploid samples and <1% for haploid samples(P < 0.001). All polyploid samples showed a typical splitting of BAF among 3 experimental ranges (20–40%,40%–60%,60–80%): 34.1%,18.2% and 47.7%, respectively. For microdeletions, all interstitial SNPs genotyped showed a loss of heterozygosity (LOH) as expected. The analysis of positive controls consisting of 20 blastocyst rebiopsies and 3 cell lines (–4p: n = 3; –8q: n = 4; –1p: n = 5; –22q: n = 3; –5p: n = 2; –15q: n = 4; –11q: n = 2), allowed to accurately characterize 6 out of the 7 microdeletions (18/23 samples). In particular, all interstitial SNPs genotyped showed a LOH, while diploid controls showed an overall heterozygosity of 30.9% (average number of hetSNP x deletion=9/28). Only the very small telomeric 1p36 region failed to properly amplify. For monogenic conditions, sequencing analysis of 5 positive gDNA controls confirmed the presence of 4 known SNVs, whilst only 1 did not achieve the minimum coverage for variant calling. Moreover, 4 additional de novo SNVs detected by sequencing analysis in the gene panel on 8 blastocyst rebiopsies were all confirmed by qPCR/Taqman assays.

Limitations, reasons for caution

Positive controls were not available for all genes and microdeletions included in the panel. Moreover, inefficient amplification has affected some target regions and further optimization will be required. However, analytical performance on technical and biological replicates were highly promising for the tested conditions both cell lines and trophectoderm biopsies.

Wider implications of the findings: This study demonstrates that the integration of genotyping and chromosomal analyses can be efficiently achieved in the same NGS workflow. This approach can be employed to expand PGT diagnostic scope to conditions undetectable in parents due to their de novo onset, or that are below the standard PGT-A resolution.

Trial registration number

N/A

P–210 Abnormal cleavage patterns during embryo preimplantation development and their effect on blastulation: an overview from IVF patients with multiple IVF cycles in a time-lapse incubator

Study question

How common abnormal cleavage patterns (ACP) are in IVF and what are their consequences on embryo developmental competence?

Summary answer

ACP might affect up to 25% of the 2PN-zygotes, independently from patients’/cycles’ characteristics, and mostly cause embryo developmental arrest around the 4-to–8-cell transition.

What is known already

Since its implementation in IVF, time-lapse-microscopy (TLM) allowed the standardization of embryo culture within undisturbed incubators, but it has not improved embryo selection especially if blastocyst transfer is performed. Nevertheless, TLM holds the potential for boosting our knowledge of embryo preimplantation development. In particular, a continuous observation of embryo morpho-dynamics unveiled peculiar blastomere cleavage patterns previously unidentifiable with a static morphological assessment. These events are possibly associated with massive mitotic errors, affecting both chromosomes and cytoskeletal components, as well as downstream metabolic imbalances. Still, the causes of ACP and their consequences on embryo developmental/reproductive competence require further investigation.

Study design, size, duration

Observational study including 75 patients (age:38.6±3.7yr, FSH:8.8±3.6IU/l, AMH:1.7±1.3ng/ml; BMI:21.4±2.4) who conducted multiple IVF cycles (N = 160; 8.7±5.0 cumulus-oocyte-complexes and 6.3±3.6 metaphase-II collected; 201±245 days between first and second cycles) in a time-lapse incubator between 2014–2020. All annotations were performed blindly by two operators and confirmed by a third in case of discordance. The outcomes were the blastulation rate after any ACP, their association between each other and with patients’/cycles’ characteristics.

Participants/materials, setting, methods

We included only ICSI-cycles after ovarian-stimulation with blastocyst culture conducted in the Embryoscope. Overall, 981 metaphase-II were inseminated and 677 2PN-zygotes annotated. The ACP investigated were: (i)cytokinesis-failure, formation of cytoplasmic septa without cell division; (ii)Chaotic-cleavage, disordered and uneven cleavages; (iii)Direct-unequal-cleavage (DUC), cleavage of zygotes or single blastomeres directly into 3; (iv)Rapid-cleavage, t3-t2<5hr; (v)Reverse-cleavage, fusion of 2 blastomeres into 1; (vi)Fragmentation, presence of numerous non-nucleated fragments; (vii)Blastomeres’ exclusion/extrusion, nucleated cells excluded/extruded from the morula.

Main results and the role of chance

Among the 2PN-zygotes, the prevalence of cytokinesis-failure was 5.9% (N = 40/677), 15.7% for chaotic-cleavage (N = 106/677), 18.6% for DUC (N = 126/677), 4.1% for rapid-cleavage (N = 28/677), 3.5% for reverse-cleavage (N = 24/677) and 24.1% for fragmentation (N = 163/677). Among the morulae, the prevalence of blastomere exclusion/extrusion was 27% (N = 109/410;1.5±1.2 excluded/extruded cells,range:1–7). The risk for reverse-cleavage was higher among 2PN-zygotes facing failed-cytokinesis (N = 8/40,20% versus N = 16/637,2.5%, OR:9.7,95%CI:3.9–24.3,p<0.01). Fragmentation was instead higher among 2PN-zygotes undergoing chaotic cleavage (N = 47/106,44.3% versus N = 116/571,20.3%, OR:3.1,95%CI:2–4.8,p<0.01) or DUC (N = 46/126,36.5% versus N = 117/551,21.2%, OR:2.1,95%CI:1.4–3.2,p<0.01). Lastly, higher prevalence of blastomeres’ exclusion/extrusion were reported among morulae obtained after chaotic-cleavage (N = 17/29,58.6% versus N = 92/381,24.1%, OR:4.4,95%CI:2–9.7,p<0.01), DUC (N = 26/37,70.3% versus N = 83/373,22.3%, OR:8.3,95%CI:3.9–17.4,p<0.01) and in presence of fragmentation (N = 79/195,75.2% versus N = 30/305,9.8%, OR:27.8,95%CI:15.6–49.8,p<0.01); only a higher trend after rapid-/reverse-cleavage.

No predictive factor of ACP was identified among patients’ and cycles’ characteristics, except for higher risks of fragmentation (OR:2.6,95%CI:1.1–6.3,p= 0.04) and blastomeres’ exclusion/extrusion (OR:2.7,95%CI:1.1–7.2,p=0.04) among patients with previous experience with these events.

The viable-blastocyst rate per 2PN-zygote was 45.1% (N = 305/677). It was lower in case of failed-cytokinesis (N = 12/40,30% versus N = 293/637,46%, OR:0.5,95%CI:0.25–0.99,p=0.05), chaotic cleavage (N = 20/106,18.9% versus N = 285/571,49.9%, OR:0.23,95%CI:0.14–0.39,p<0.01), DUC (N = 27/126,21.4% versus N = 278/551,50.5%, OR:0.27,95%CI:0.17–0.42,p<0.01), rapid-cleavage (N = 6/22,21.4% versus N = 299/649,46.1%, OR:0.32,95%CI:0.13–0.8,p=0.02), and reverse-cleavage (N = 5/19,20.8% versus N = 300/653,45.9%, OR:0.31, 95%CI:0.11–0.84,p=0.02). No difference was instead shown in case of fragmentation and/or blastomeres’ exclusion/extrusion.

Limitations, reasons for caution

The patients included were poor-prognosis women undergoing ≥2 cycles. We are expanding the sample size to account for all cycles conducted in time-lapse incubators. Larger sample size will provide also statistical-power to investigate the effect of ACP on blastocysts’ chromosomal and implantation competence, and more visualizations of rapid-/reverse-cleavage events.

Wider implications of the findings: After ACP,developmental-arrest mostly occurs around the 4-to–8-cell transition (50–70% versus ∼30%), when embryonic-genome-activation takes place. Surviving embryos often fragment and/or exclude/extrude blastomeres at morulation, without further impact on blastulation-rates. Moreover, ACP seem independent from patients’/cycles’ characteristics. These evidence incite future Research on the biological/genetic mechanisms triggering ACP and their consequences.

Trial registration number

None

Clinical validity and utility of preconception expanded carrier screening for the management of reproductive genetic risk in IVF and general population

STUDY QUESTION

What is the clinical validity and utility of preconception Expanded Carrier Screening (ECS) application on the management of prospective parents?

SUMMARY ANSWER

The high detection rate of at-risk couples (ARCs) and the high proportion opting for IVF/preimplantation genetic testing (PGT) treatment demonstrate the clinical utility of ECS in the preconception space in IVF and general population.

WHAT IS KNOWN ALREADY

About 2-4% of couples are at risk of conceiving a child with an autosomal recessive or X-linked genetic disorder. In recent years, the increasing cost-effectiveness of genetic diagnostic techniques has allowed the creation of ECS panels for the simultaneous detection of multiple recessive disorders. Comprehensive preconception genetic screening holds the potential to significantly improve couple's genetic risk assessment and reproductive planning to avoid detectable inheritable genetic offspring.

STUDY DESIGN, SIZE, DURATION

A total of 3877 individuals without a family history of genetic conditions were analyzed between January 2017 and January 2020. Of the enrolled individuals, 1212 were gamete donors and 2665 were patients planning on conceiving from both the IVF and the natural conception group. From the non-donor cohort, 1133 were analyzed as individual patients, while the remaining ones were analyzed as couples, for a total of 766 couples.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A focused ECS panel was developed following American College of Obstetrics and Gynecology ACOG-recommended criteria (prevalence, carrier rate, severity), including highly penetrant severe childhood conditions. Couples were defined at-risk when both partners carried an autosomal recessive pathogenic/likely pathogenic variant (PLP) on the same gene or when the woman was a carrier of an X-linked PLP variant. ARC detection rate defined the clinical validity of the ECS approach. Clinical utility was evaluated by monitoring ARCs reproductive decision making.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 402 individuals (10.4%) showed PLP for at least one of the genes tested. Among the 766 couples tested, 173 showed one carrier partner (22.6%), whereas 20 couples (2.6%) were found to be at increased risk. Interestingly, one ARC was identified as a result of cascade testing in the extended family of an individual carrying a pathogenic variant on the Survival Of Motor Neuron 1SMN1 gene. Of the identified ARCs, 5 (0.7%) were at risk for cystic fibrosis, 5 (0.7%) for fragile X syndrome, 4 (0.5%) for spinal muscular atrophy, 4 (0.5%) for Beta-Thalassemia/Sickle Cell Anemia, 1 (0.1%) for Smith-Lemli-Opitz Syndrome and 1 (0.1%) for Duchenne/Becker Dystrophy. Fifteen ARCs were successfully followed up from both the IVF and the natural conception groups. All of these (15/15) modified their reproductive planning by undergoing ART with Preimplantation Genetic Testing for Monogenic disease and Aneuploidies (PGT-M and PGT-A). To date, 6/15 (40%) couples completed their PGT cycle with euploid/unaffected embryos achieving a pregnancy after embryo transfer and three of them have already had an unaffected baby.

LIMITATIONS, REASONS FOR CAUTION

The use of a limited panel of core gene-disease pairs represents a limitation on the research perspective as it can underestimate the rate of detectable carriers and ARCs in this cohort of prospective parents. Expanding the scope of ECS to a larger panel of conditions is becoming increasingly feasible, thanks to a persistent technological evolution and progressive cataloging of gene-disease associations.

WIDER IMPLICATIONS OF THE FINDINGS

These results highlight the potential clinical validity and utility of ECS in reducing the risk of a pregnancy affected by a detectable inheritable genetic condition. The steady reduction in the costs of genetic analyses enables the expansion of monogenic testing/screening applications at the preimplantation stage, thus, providing valid decisional support and reproductive autonomy to patients, particularly in the context of IVF.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. A.C., M.F., S.C., M.P., L.G., and C.P. are employees of Igenomix Italy. C.S. is the head of the scientific board of Igenomix.

TRIAL REGISTRATION NUMBER

N/A.

An integrated investigation of oocyte developmental competence: expression of key genes in human cumulus cells, morphokinetics of early divisions, blastulation, and euploidy

PURPOSE

To investigate the association of cumulus cell (CC)-related expression of a selected cluster of key genes (PTGS2, CAMK1D, HAS2, STC1, and EFNB2) with embryo development to blastocyst.

METHODS

Exploratory study at a private clinic. Eighteen advanced maternal age patients were enrolled (37.3 ± 4.0 years). Seventy-five cumuli were collected, whose oocytes resulted in either developmental arrest (N = 33) or blastocyst formation (N = 42). The noninvasive CC gene expression was combined with time-lapse morphokinetic parameters and, for blastocysts, with qPCR-based aneuploidy testing on trophectoderm biopsies.

RESULTS

The detection rate was 100% for all transcripts, but STC1 (96%) and CAMK1D (89%). Among amplified assays, CC mean expression levels of CAMK1D, PTGS2, and HAS2 were higher from oocytes that developed to blastocyst. No difference in CC key gene expression was reported between euploid (N = 21) and aneuploid (N = 21) blastocysts. Some timings of early embryo development were faster in embryos developing to blastocyst (time of pronuclei appearance and fading, division to two- and four-cells, first and second cell cycles). However, the generalized linear models outlined increasing CAMK1D expression levels as the strongest parameter associated with oocytes' developmental potential from both a general (AUC = 0.78 among amplified samples) and an intrapatient perspectives (AUC = 0.9 among patients obtaining ≥ 2 zygotes from the cohort with different developmental outcomes).

CONCLUSIONS

CAMK1D level of expression in CCs associated with blastocyst development. If confirmed from larger studies in wider populations of patients, the investigation of CC key gene expression might suit IVF clinics not adopting blastocyst culture. Future investigations should clarify the role of CAMK1D in ovarian physiology and could provide novel insights on how oocytes gain competence during folliculogenesis.

Prevention of neural tube defects and maternal gestational diabetes through the inositol supplementation: preliminary results

OBJECTIVE

Our study aims to demonstrate that the use in the preconceptional period until the 24th week of pregnancy of inositol and folic acid, first of all, preserves the product of conception from neural tube defects (NTDs) and then, thanks to inositol supplementation, it possibly counteracts and prevents the onset of maternal gestational diabetes (GDM).

PATIENTS AND METHODS

We have collected data derived from pregnant women arrived at our laboratory, from January 2014 to January 2016, with no family history of type 2 diabetes and hypertension. The first group (n = 68 women) was treated from the preconceptional period until the 24th week of pregnancy with 1.75 g/day myo-inositol, 250 mg/day D-chiro-inositol, 12.5 mg/day Zinc pidolate, 100 mg/day methylsulfonylmethane, 120 mg/day Vitamin C and 400 mcg/day (6S)-5-methyltetrahydrofolic acid. The control group (n = 72) was only treated with 400 mcg/day folic acid. The main outcome measure was the prevalence of maternal GDM. Secondary outcome measures were the prevalence of NTDs and fetal macrosomia.

RESULTS

A significant difference was found regarding body mass index (BMI), fasting oral glucose tolerance test (OGTT), after 1-h-glucose OGTT, 2-h-glucose OGTT, glycated hemoglobin (HbA1c) and serum folate, between the two groups. Five infants, in the control group, weighted greater than 4 kg. Moreover, we found a positive correlation between HbA1c and OGTT at the 24th week of pregnancy.

CONCLUSIONS

This study shows the efficacy of preconceptional supplementation of inositol to reduce the risk of the onset of GDM and to confirm the importance of folic acid supplementation to avoid NTDs development. Moreover, the positive correlation between HbA1c and OGTT may be useful to consider the use of HbA1c as a single tool for GDM prevention and diagnosis in selected woman in pregnancy.

The 312N variant of the luteinizing hormone/choriogonadotropin receptor gene (LHCGR) confers up to 2·7-fold increased risk of polycystic ovary syndrome in a Sardinian population

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a frequent condition, affecting about 15% of women of reproductive age. Because of its familial occurrence, a multifactorial model of susceptibility, including both genetic and environmental factors, has been proposed. However, the identification of genetic factors has been elusive.

DESIGN

Case-control study aimed at evaluating possible associations between functionally relevant variants of the luteinizing hormone/choriogonadotrophin receptor gene (LHCGR) and PCOS phenotype.

PATIENTS

A total of 198 PCOS and 187 non-PCOS women, aged 14-35 years, of Sardinian origin, were referred to the outpatient clinic of the Department of Obstetrics and Gynaecology of the University of Cagliari (Sardinia). PCOS diagnosis was based on the Rotterdam criteria.

MEASUREMENTS

We determined the genotype of ins18LQ, S291N and S312N variants at the LHCGR locus. Genotype was related to the presence or absence of PCOS and to several clinical and biochemical characteristics.

RESULTS

The presence of at least one 312N allele was strongly associated with PCOS risk (OR, 2·04; 95% CI, 1·32-3·14; χ(2) , 10·47; P = 0·001). 312N homozygosity was associated with a further risk increase (OR, 2·73; 95% CI, 1·25-5·95; χ(2) , 6·65; P = 0·01). The number of ins18LQ alleles was associated with LH serum levels in controls (χ(2) , 8·04, P = 0·017).

CONCLUSIONS

For the first time, we have identified a genetic variant that is strongly associated with PCOS in an isolated population. These results, if confirmed in other cohorts, may provide the opportunity to test the S312N genotype at the LHCGR locus in fertile women to assess the risk of PCOS. The avoidance of triggering factors like weight increase may improve the reproductive outcome of potentially at-risk subjects.

Prenatal diagnosis and molecular characterization of an interstitial 1q24.3-31.3 deletion: case report and review

We describe a foetus with an interstitial deletion of 1q detected in amniotic fluid cells and we review the literature of similar pre- and postnatal cases, in order to identify prognostic factors useful for prenatal counselling. Foetal/parents karyotyping and FISH with whole chromosome 1 paint and BAC clone specific for 1q23-32 region were performed. Further 100 Kb resolution array-CGH analysis was executed after pregnancy termination on DNA extracted from foetal skin fibroblasts. Cytogenetic analyses revealed a de novo interstitial deletion involving the long arm of chromosome 1. FISH analysis confirmed that the deletion involves the intermediate 1q31.2 region. Foetal ultrasound (US), performed at 21 weeks of gestation, showed intrauterine growth restriction, shortening of the long bones, echogenic intracardiac focus and mild cerebral ventriculomegaly. Array-CGH localized the deletion in a DNA sequence of about 21 Mb in the 1q24.3-q31.3 region. Our findings, together with available data on patients with 1q deletion, suggest that the most severe phenotypes are not simply associated with larger deletion, and that the results of prenatal US assessment, rather than a fine molecular characterization of the deletion, should be taken into account for prognostic evaluation.

Leisure time but not occupational physical activity significantly affects cardiovascular risk factors in an adult population

BACKGROUND

A large number of studies have demonstrated that regular physical activity during leisure time (LTPA) accounts for a significant protection against cardiovascular diseases (CVD). On the other hand, conflicting findings on the beneficial effects of occupational physical activity (OPA) have been reported. The aim of this study is to evaluate the possible influence of different amounts of LTPA and OPA on circulating levels of several parameters associated with an increased risk of CVD.

MATERIALS AND METHODS

We studied 932 individuals (365 M; 567 F, with a mean age of 54 years) living in Florence, Italy, who were enrolled in a population study conducted between 2002 and 2004. Subjects were divided into three classes of LTPA and OPA according to a score derived from a questionnaire that assessed the amount of physical activity performed.

RESULTS

LTPA was inversely related to body mass index (BMI), hip circumference, diastolic blood pressure and triglycerides, as well as directly correlated with high-density lipoprotein (HDL) cholesterol. Likewise, a higher OPA was found to be associated with higher HDL cholesterol levels. Moreover, a multivariate logistical regression analysis, adjusted for possible confounders, showed that a moderate-to-high intensity of LTPA was able to confer a significant protection against having abnormal levels of BMI, waist circumference and triglycerides, main features of the metabolic syndrome, whereas no associations between these parameters and OPA were observed.

CONCLUSIONS

A moderate-to-high LTPA was found to be significantly associated with a more favourable cardiovascular risk profile in terms of anthropometric, metabolic and lipid parameters among an Italian population. In addition, a relationship between OPA and HDL-cholesterol was reported.

RAS genes influence exercise-induced left ventricular hypertrophy: an elite athletes study

PURPOSE

The association of ACE I/D polymorphism with changes in LV mass in response to physical training has been observed, but no association has been found with AT1R A1166C polymorphism. We investigated the ACE I/D, AT1R A1166C, and AT1R CA microsatellite polymorphisms genotype distribution in elite athletes and whether the presence of AT1R C1166 variant, in addition to ACE D allele affects the training-induced LV mass alterations in elite trained athletes.

METHODS

The study population comprised 28 healthy players recruited from an Italian elite male soccer team and 155 healthy male subjects. LV mass, LV mass adjusted for body surface area, septal thickness, posterior wall, end-diastolic and end-systolic ventricular dimension, and ejection fraction were determined by echocardiography in pretrained period, at rest and 7 months later during the training. All subjects were genotyped for ACE I/D, AT1R A1166C, and CA microsatellite polymorphisms.

RESULTS

Training induced an LV mass increase in all but six athletes. The percentage of athletes in whom an increase of LV mass was found after training was statistically different in relation to the ACE D allele: no increase was observed in three of 24 D allele carriers and in three of four II genotype players (Fisher's exact test, P = 0.02). As AT1R is concerned, no increase was observed in 4 of 15 C allele carriers and in 2 of 13 AA genotype athletes (Fisher's exact test, P > 0.05). The contemporary presence of ACE D and AT1R C allele did not affect the changes after training. No difference has been observed in the CA microsatellite marker allele frequencies between athletes and controls (P = 0.46).

CONCLUSION

In this study, we provide the evidence that soccer play does not select athletes on genotype basis. Training-induced LV mass changes in male elite athletes are significantly associated with the presence of ACE D allele, but not of AT1R C allele.

[The effects of training on skeletal and cardiac muscle mass in professional soccer players]

Ongoing physical exercise is able to increase skeletal and cardiac muscle mass. Echocardiography and body impedance analysis permit non-invasive evaluation of these two parameters. The aim of this study was to evaluate the effects of training and detraining on the heart and skeletal muscles of professional soccer players. Twenty-one professional athletes (average age 24 +/- 3.5 years) were evaluated during five different phases of their athletic training and compared with 21 age- and height-matched healthy, non-obese sedentary subjects. All subjects underwent measurement of body mass distribution by means of bioelectrical impedance analysis and of left ventricular mass by means of echocardiography. The control group had lower values of lean and cellular body mass, as well as lower left ventricular mass than the professional athletes. Over the 13-month study period, the athletes showed no substantial modifications in fat and muscle mass parameters. Instead, left ventricular mass values increased during the playing season, evidencing physiological hypertrophy after 6 months of competitive activity. No subsequent increases were observed over the next 2 months, and after detraining, left ventricular mass returned to baseline values. We thus conclude that exercise training brings about changes in cardiac mass without producing parallel changes in skeletal muscular mass.