Non-invasive cumulus cell analysis can be applied for oocyte ranking and is useful for countries with legal restrictions on embryo generation or freezing.

RESEARCH QUESTION: Can a strategy for scoring oocyte quality, based on cumulus cell (CC) gene expression, prioritize oocytes with the highest implantation potential, while limiting the number of embryos to be processed in culture and the number of supernumerary embryos to be vitrified? DESIGN: An interventional, blinded, prospective cohort study was retrospectively analyzed. In the original study, patients underwent a fresh Day3 single embryo transfer with embryos ranked based on morphology and CC gene expression (Aurora Test). The additional ranking of the embryos with the Aurora Test resulted in significant higher clinical pregnancy and live birth rates. Now it is investigated if the Aurora Test ranking could be applied to select oocytes. The effect of an Aurora Test based restriction to 2 and 3 2PN or MII oocytes on clinical pregnancy and other outcomes, was analyzed in two subsets of patients with all 2PN (n = 83) or all MII oocytes (n = 45) ranked. RESULTS: Considering only the top three ranked 2PN oocytes, 95% of the patients would have received a fresh SET on Day3 resulting in 65% clinical pregnancies. This was not different from the pregnancy rate obtained in a strategy using all oocytes but significantly reduced the need for vitrification of supernumerary embryos by 3-fold. Considering only top-ranked MII oocytes gave similar results. CONCLUSIONS: In countries with legal restrictions on freezing of embryos, gene expression of CC can be used for the selective processing of oocytes and would thus decrease the twin pregnancy rate and workload, especially for embryo morphology scoring and transfers as the handling and processing of lower competence oocytes is prevented, while improving the ART outcome.

Lineage segregation in human pre-implantation embryos is specified by YAP1 and TEAD1.

STUDY QUESTION: Which processes and transcription factors specify the first and second lineage segregation events during human preimplantation development? SUMMARY ANSWER: Differentiation into trophectoderm (TE) cells can be initiated independently of polarity; moreover, TEAD1 and YAP1 co-localize in (precursor) TE and primitive endoderm (PrE) cells, suggesting a role in both the first and the second lineage segregation events. WHAT IS KNOWN ALREADY: We know that polarity, YAP1/GATA3 signalling and phospholipase C signalling play a key role in TE initiation in compacted human embryos, however, little is known about the TEAD family of transcription factors that become activated by YAP1 and, especially, whether they play a role during epiblast (EPI) and PrE formation. In mouse embryos, polarized outer cells show nuclear TEAD4/YAP1 activity that upregulates Cdx2 and Gata3 expression while inner cells exclude YAP1 which upregulates Sox2 expression. The second lineage segregation event in mouse embryos is orchestrated by FGF4/FGFR2 signalling which could not be confirmed in human embryos; TEAD1/YAP1 signalling also plays a role during the establishment of mouse EPI cells. STUDY DESIGN, SIZE, DURATION: Based on morphology, we set up a development timeline of 188 human preimplantation embryos between Day 4 and 6 post-fertilization (dpf). The compaction process was divided into three subgroups: embryos at the start (C0), during (C1), and at the end (C2) of, compaction. Inner cells were identified as cells that were entirely separated from the perivitelline space and enclosed by cellular contacts on all sides. The blastulation process was divided into six subgroups, starting with early blastocysts with sickle-cell shaped outer cells (B0) and further on, blastocysts with a cavity (B1). Full blastocysts (B2) showed a visible ICM and outer cells referred to as TE. Further expanded blastocysts (B3) had accumulated fluid and started to expand due to TE cell proliferation and zona pellucida (ZP) thinning. The blastocysts then significantly expanded further (B4) and started to hatch out of the ZP (B5) until they were fully hatched (B6). PARTICIPANTS/MATERIALS, SETTING, METHODS: After informed consent and the expiration of the 5-year cryopreservation duration, 188 vitrified high quality eight-cell stage human embryos (3 dpf) were warmed and cultured until the required stages were reached. We also cultured 14 embryos that were created for research until the four- and eight-cell stage. The embryos were scored according to their developmental stage (C0-B6) displaying morphological key differences, rather than defining them according to their chronological age. They were fixed and immunostained for different combinations of cytoskeleton (F-actin), polarization (p-ERM), TE (GATA3), EPI (NANOG), PrE (GATA4 and SOX17), and members of the Hippo signalling pathway (YAP1, TEAD1 and TEAD4). We choose these markers based on previous observations in mouse embryos and single cell RNA-sequencing data of human embryos. After confocal imaging (LSM800, Zeiss), we analysed cell numbers within each lineage, different co-localization patterns and nuclear enrichment. MAIN RESULTS AND THE ROLE OF CHANCE: We found that in human preimplantation embryos compaction is a heterogeneous process that takes place between the eight-cell to the 16-cell stages. Inner and outer cells are established at the end of the compaction process (C2) when the embryos contain up to six inner cells. Full apical p-ERM polarity is present in all outer cells of compacted C2 embryos. Co-localization of p-ERM and F-actin increases steadily from 42.2% to 100% of the outer cells, between C2 and B1 stages, while p-ERM polarizes before F-actin (P < 0.00001). Next, we sought to determine which factors specify the first lineage segregation event. We found that 19.5% of the nuclei stain positive for YAP1 at the start of compaction (C0) which increases to 56.1% during compaction (C1). At the C2 stage, 84.6% of polarized outer cells display high levels of nuclear YAP1 while it is absent in 75% of non-polarized inner cells. In general, throughout the B0-B3 blastocyst stages, polarized outer/TE cells are mainly positive for YAP1 and non-polarized inner/ICM cells are negative for YAP1. From the C1 stage onwards, before polarity is established, the TE marker GATA3 is detectable in YAP1 positive cells (11.6%), indicating that differentiation into TE cells can be initiated independently of polarity. Co-localization of YAP1 and GATA3 increases steadily in outer/TE cells (21.8% in C2 up to 97.3% in B3). Transcription factor TEAD4 is ubiquitously present throughout preimplantation development from the compacted stage onwards (C2-B6). TEAD1 displays a distinct pattern that coincides with YAP1/GATA3 co-localization in the outer cells. Most outer/TE cells throughout the B0-B3 blastocyst stages are positive for TEAD1 and YAP1. However, TEAD1 proteins are also detected in most nuclei of the inner/ICM cells of the blastocysts from cavitation onwards, but at visibly lower levels as compared to that in TE cells. In the ICM of B3 blastocysts, we found one main population of cells with NANOG+/SOX17-/GATA4- nuclei (89.1%), but exceptionally we found NANOG+/SOX17+/GATA4+ cells (0.8%). In seven out of nine B3 blastocysts, nuclear NANOG was found in all the ICM cells, supporting the previously reported hypothesis that PrE cells arise from EPI cells. Finally, to determine which factors specify the second lineage segregation event, we co-stained for TEAD1, YAP1, and GATA4. We identified two main ICM cell populations in B4-6 blastocysts: the EPI (negative for the three markers, 46.5%) and the PrE (positive for the three markers, 28.1%) cells. We conclude that TEAD1 and YAP1 co-localise in (precursor) TE and PrE cells, indicating that TEAD1/YAP1 signalling plays a role in the first and the second lineage segregation events. LIMITATIONS, REASONS FOR CAUTION: In this descriptive study, we did not perform functional studies to investigate the role of TEAD1/YAP1 signalling during the first and second lineage segregation events. WIDER IMPLICATIONS OF THE FINDINGS: Our detailed roadmap on polarization, compaction, position and lineage segregation events during human preimplantation development paves the way for further functional studies. Understanding the gene regulatory networks and signalling pathways involved in early embryogenesis could ultimately provide insights into why embryonic development is sometimes impaired and facilitate the establishment of guidelines for good practice in the IVF lab. STUDY FUNDING/COMPETING INTERESTS: This work was financially supported by Wetenschappelijk Fonds Willy Gepts (WFWG) of the University Hospital UZ Brussel (WFWG142) and the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO, G034514N). M.R. is doctoral fellow at the FWO. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Impact of embryo vitrification on children's health, including growth up to two years of age, in comparison with results following a fresh embryo transfer.

OBJECTIVE: To assess health outcomes, including growth up to 2 years of age, in children born after embryo vitrification in comparison with children born after fresh embryo transfer. DESIGN: A prospective cohort study. SETTING: A single-center university hospital. PATIENT(S): Singletons born after the transfer of vitrified or fresh embryos, either at the cleavage or blastocyst stage between 2014 and 2018, were included. INTERVENTION(S): Multiple linear and logistic regression analyses were used to study the association between outcomes after vitrified versus fresh embryo transfer, controlling for neonatal, treatment, and maternal characteristics. Subgroup analysis according to cycle protocol (hormone replacement vs. natural cycle) and strategy (freeze-all vs. previous fresh cycle) was also performed. MAIN OUTCOME MEASURE(S): Measurements at birth and growth in infancy and childhood, as well as health outcomes, including congenital malformations, interventions, medication use, and hospitalizations are reported. RESULT(S): Birth characteristics were available for 1237 and 2063 children born after embryo vitrification and fresh embryo transfer, respectively. Follow-up data were available for 582 and 757 children at infancy and for 233 and 296 children at 2 years, respectively. Birthweight, height, and head circumference SD scores of children born after embryo vitrification were higher than children born after fresh embryo transfer, even after adjustment for neonatal, treatment, and maternal characteristics. In infancy, weight and height SD scores were larger for children born after embryo vitrification, but not after adjustment for covariates. In childhood, no differences in anthropometry were observed between the groups. Weight and height gain from birth to infancy and from infancy to early childhood were comparable between the groups. Comparable rates of severe developmental problems, hospital admissions, surgical interventions, and of chronic medication use were observed up to the age of 2 years. Subgroup analysis showed that growth parameters were not affected by the cycle protocol or strategy at any age. CONCLUSION(S): Our study indicated that embryo vitrification is associated with higher birthweight, even after controlling for confounders. However, in early childhood, anthropometry and weight and height gain was not different in children born after vitrified or fresh embryo transfer.

Effect of A23187 ionophore treatment on human blastocyst development-a sibling oocyte study.

PURPOSE: To investigate whether treatment with commercially available ready-to-use A23187 ionophore (GM508-CultActive) improves embryo development outcome in patients with a history of embryo developmental problems. METHODS: This is a uni-center prospective study in which sibling oocytes of patients with embryos of poor quality on day 5 in the previous cycle were treated or not with CultActive. RESULTS: Two hundred forty-seven metaphase II (MII) oocytes from 19 cycles performed between 2016 and 2019 were included in the study. After ICSI, the sibling oocytes were assigned to the treatment group or to the control group, following an electronically generated randomization list. A number of 122 MII were treated with CultActive and 125 MII had no treatment and were assigned to the control group. No difference in fertilization rate (p = 0.255) or in the capacity of embryos to reach good quality on day 5 (p = 0.197) was observed between the two groups. The utilization rates defined as the number of embryos transferred or cryopreserved per mature oocyte (p = 0.438) or per fertilized oocytes (p = 0.299) were not significantly different between the treated group and the control group. CONCLUSION: The results of the current study do not support the use of CultActive in cases with embryo developmental problems.

Follitropin alpha versus beta in a first GnRH antagonist ICSI cycle: a retrospective cohort study.

RESEARCH QUESTION: Are cumulative live birth rates (CLBR) after follitropin alpha (Ovaleap®) and follitropin beta (Puregon®) similar when used for ovarian stimulation with ICSI (intracytoplasmic sperm injection) in a first-rank gonadotrophin-releasing hormone (GnRH) antagonist protocol? DESIGN: Retrospective single-centre cohort study including 832 infertile patients undergoing ovarian stimulation with a daily dose of 150-225 IU FSH in their first ICSI cycle at a tertiary referral centre between July 2016 and July 2019. Of those, 349 patients used Ovaleap and 483 patients received Puregon. RESULTS: Baseline characteristics were not statistically different between the groups. The duration of stimulation was slightly longer in the Ovaleap group (10.6 ± 1.7 versus 10.3 ± 1.6 days; P = 0.012). The number of mature oocytes was not statistically different and there was no significant difference in fertilization rate or embryo utilization rate between the two groups. After fresh embryo transfer, biochemical pregnancy rate (137/349 [39.3%] versus 186/483 [38.5%]) as well as clinical pregnancy rate (105/349 [30.1%] versus 152/483 [31.5%]) were comparable (P = 0.83 and 0.67, respectively). Live birth rate (LBR) after fresh embryo transfer (94/349 [26.9%] versus 141/483 [29.2%]; P = 0.48) and CLBR (199/349 [57.0%] versus 287/483 [59.4%]; P = 0.49) were not significantly different. Multivariable regression analysis revealed that the type of gonadotrophin was not associated with CLBR (P = 0.28). CONCLUSION: This retrospective study shows no significant difference in CLBR between Ovaleap and Puregon in patients undergoing their first GnRH antagonist ICSI cycle.

Erratum to: Health of 2-year-old children born after vitrified oocyte donation in comparison with peers born after fresh oocyte donation.

[This corrects the article DOI: 10.1093/hropen/hoab002.].

Androgens and Anti-Müllerian Hormone in Infertile Patients.

To investigate whether there is an association between androgens and ovarian reserve, expressed through anti-Mullerian hormone. This is a retrospective cross-sectional analysis of all consecutive women attending a tertiary fertility center, who presented with regular menstrual cycles. Patients had their AMH values measured with the same AMH assay (Immunotech (IOT) Beckmann Coulter assay), the same day in which androgens sampling was performed. Women with PCOS or other forms of androgen excess or untreated endocrine or metabolic disorders were excluded. A total of 942 women were included. Significant correlation was observed between total testosterone/free androgens index (FAI)/DHEAS and AMH (Spearman's r = 0.20/0.14/0.13, P value < 0.001, P value < 0.001, and P value < 0.001, respectively). After multiple linear regression analysis adjusting for confounders (age, BMI, cause of infertility, day of the menstrual cycle when the blood sample was performed), the regression slope in all participants for total testosterone predicting logAMH was 0.20 (P value < 0.001). Similarly, FAI was significantly associated with logAMH (regression coefficient = 0.04, P value = 0.04). In contrast, DHEAS was not significantly associated with logAMH. There was a significant, but weak relation between testosterone and AMH, while no significant association was observed between DHEAS and AMH. Future research is needed to elucidate whether testosterone supplementation may have any effect on ovarian function.

Health of 2-year-old children born after vitrified oocyte donation in comparison with peers born after fresh oocyte donation.

STUDY QUESTION: Does oocyte vitrification adversely affect the health of 2-year-old children compared with peers born after use of fresh oocytes in a donation programme? SUMMARY ANSWER: The growth and health of 2-year-old children born after oocyte vitrification are similar to those of peers born after use of fresh oocytes. WHAT IS KNOWN ALREADY: Although oocyte vitrification is a well-established procedure in ART, the evidence on its safety for offspring is limited. Currently, no disadvantageous effects of oocyte vitrification have been shown in terms of obstetric and neonatal outcome. However, no data beyond the neonatal period are available to date. STUDY DESIGN SIZE DURATION: A combined retrospective and prospective observational study was performed in a tertiary reproductive centre. The retrospective data were available in our extensive database of children born after ART. Donor cycles with an oocyte retrieval between January 2010 and March 2017 and a fresh embryo transfer resulting in the livebirth of a singleton were selected from the established oocyte donation programme. Fresh or vitrified oocytes were used in the donor cycles and all pregnancies in oocyte recipients were achieved after ICSI. Only children residing in Belgium were eligible for follow-up. PARTICIPANTS/MATERIALS SETTING METHODS: Biometric and health parameters of 72 children born after oocyte vitrification were compared with those of 41 children born after use of a fresh oocyte. Data were collected by means of questionnaires and physical examinations at the age of 21-30 months. The primary outcome measures were anthropometry and health at 2 years of age. MAIN RESULTS AND THE ROLE OF CHANCE: Length, weight, BMI, head circumference, left arm circumference and waist circumference at the age of 2 years were comparable between the vitrification and fresh group, also after adjustment for treatment, and maternal and neonatal characteristics (all P > 0.05). Health of the children in terms of hospital admission and surgical intervention rates were comparable between the vitrification and fresh group (both P > 0.05). LIMITATIONS REASONS FOR CAUTION: Although the current study is the largest series describing health parameters beyond the neonatal period, the small numbers still preclude definite conclusions. WIDER IMPLICATIONS OF THE FINDINGS: This study provides the first evidence indicating that oocyte vitrification does not adversely affect the growth and health of offspring beyond the neonatal period. STUDY FUNDING/COMPETING INTERESTS: This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts, all issued by the Vrije Universiteit Brussel. All co-authors declared no conflict of interest in relation to this work. Both the Centre for Reproductive Medicine and the Centre for Medical Genetics from the UZ Brussel have received several educational grants from IBSA, Ferring, MSD and Merck for either research on oocyte vitrification or for establishing the database for follow-up research and organizing the data collection.

Improved clinical outcomes after non-invasive oocyte selection and Day 3 eSET in ICSI patients.

BACKGROUND: Non-invasive oocyte quality scoring, based on cumulus gene expression analysis, in combination with morphology scoring, can increase the clinical pregnancy (CPR) and live birth rates (LBR) in Day 3 eSET (elective single embryo transfer) ICSI patients. This was first investigated in a pilot study and is now confirmed in a large patient cohort of 633 patients. It was investigated whether CPR, LBR and time-to-pregnancy could be improved by analyzing the gene expression profile of three predictive genes in the cumulus cells, compared to patients with morphology-based embryo selection only. METHODS: A large interventional, non-randomized, assessor-blinded cohort study with 633 ICSI patients was conducted in a tertiary fertility center. Non-PCOS patients, 22-39 years old, with good ovarian reserve, were stimulated with HP-hMG using a GnRH antagonist protocol and planned for fresh Day 3 eSET. The cumulus cells from individually denuded oocytes were ranked by a lab-developed cumulus cell test: qRT-PCR for three predictive genes (CAMK1D, EFNB2 and SASH1) and two control genes (UBC, B2M). The embryo selected for transfer was highest ranked from the pool of morphologically transferable Day 3 embryos. Patients in the control (n = 520) and experimental arm (n = 113) were compared for clinical pregnancy and live birth, using a weighted generalized linear model, and time-to-pregnancy using Kaplan-Meier curves. RESULTS: The CPR was 61% in the experimental arm (n = 113) vs 29% in the control arm (n = 520, p < 0.0001). The LBR in the experimental arm (50%) was significantly higher than in the control arm (27%,p < 0.0001). Time-to-pregnancy was significantly shortened by 3 transfer cycles independent of the number of embryos available on Day 3 (Kaplan-Meier, p < 0.0001). Cumulus cell tested patients < 35 years (n = 65) or ≥ 35 years (n = 48) had a CPR of 62 and 60% respectively (ns). For cumulus cell tested patients with 2, 3-4, or > 4 transferable embryos, the CPR was 66, 52, and 67% (ns) respectively, and thus independent of the number of transferable embryos on Day 3. CONCLUSIONS: This study provides further evidence of the clinical usefulness of the non-invasive cumulus cell test over time in a larger patient cohort. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03659786 / NCT02962466 (Registered 6Sep2018/11Nov2016, retrospectively registered.

Low Testosterone and Semen Parameters in Male Partners of Infertile Couples Undergoing IVF with a Total Sperm Count Greater than 5 Million.

Low serum testosterone is found in approximately 15% of subfertile men. Although testosterone is essential in spermatogenesis, it is unclear whether low testosterone levels may have a negative impact on the semen parameters of men belonging to infertile couples with a total sperm count greater than 5 million. Furthermore, it is debatable whether the initial evaluation of the subfertile male should include an endocrine assessment. This was a retrospective, single-center cohort study conducted at a tertiary fertility clinic. Male partners of infertile couples undergoing in vitro fertilization (IVF), with a total sperm count greater than 5 million, were included. All men provided morning blood samples, and none had been on exogenous testosterone or other relevant medications. Low total testosterone (TT) was defined as <264 ng/dL. Free T was calculated using TT and sex hormone-binding globulin (SHBG) levels (nmol/L) by a constant albumin concentration of 43 g/L. In total, 853 patients were included: 116 had low TT (<264 ng/dL) and 737 had normal TT (≥264 ng/dL). Semen volume, sperm cell count, progressive (A + B) motility and morphology (≥4% strict Kruger) were lower in the low TT group but not significantly different between low and normal TT groups (3.2 ± 1.79 vs. 3.23 ± 1.64, p = 0.87; 76.82 ± 83.18 vs. 67.55 ± 57.70, p = 0.7; 54.89 ± 19.45 vs. 56.25 ± 19.03, p = 0.6; 5.77 ± 3.23 vs. 6.89 ± 3.94, p = 0.23). The percentage of patients with below-reference sperm volume (<1.5 mL), cell count (<15 × 106/mL), motility (A + B) (<32%) and morphology (<4%) was higher in the low TT group but not statistically different compared to the normal TT group. Multivariable regression analysis revealed that low TT and free T levels had no significant effect on the aforementioned semen parameters (coefficient: 3.94, 0.88, 1.37, 0.39; p = 0.53, 0.8, 0.3, 0.2; coefficient: 0.001, 0.06, 0.007, 0.0002; p = 0.73, 0.52, 0.85, 0.98). Despite our robust methodological approach, the presence of biases related to retrospective design cannot be excluded. Our findings highlighted the lack of association between low TT levels and semen parameter alterations in male partners of infertile couples undergoing IVF, with a total sperm count greater than 5 million. However, it is important to emphasize that more patients in the low TT group had subnormal semen parameters, albeit the difference was not statistically significant. Larger, prospective studies are warranted in order to validate these findings, as well as to investigate the existence of a TT threshold below which semen parameters might be negatively affected.

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.

SARS-CoV-2 host receptors ACE2 and CD147 (BSG) are present on human oocytes and blastocysts.

PURPOSE: To visualize SARS-CoV-2 host receptors ACE2 and CD147 on human oocytes and blastocysts. METHODS: Immunohistochemistry and confocal microscopy on human primary oocytes and pre (5 days post fertilization (dpf5) and (dpf6))- and peri (dpf7)-implantation blastocysts donated to research. RESULTS: SARS-CoV-2 host receptors ACE2 and CD147 are present on the membrane of trophectoderm, epiblast and hypoblast cells in human blastocysts. CD147 is also present on the oolemma. CONCLUSION: Theoretically, the earliest stages of embryonic development may be vulnerable for SARS-CoV-2 infection.

Outcome of in-vitro oocyte maturation in patients with PCOS: does phenotype have an impact?

STUDY QUESTION: Does the phenotype of patients with polycystic ovary syndrome (PCOS) affect clinical outcomes of ART following in-vitro oocyte maturation? SUMMARY ANSWER: Cumulative live birth rates (CLBRs) after IVM were significantly different between distinct PCOS phenotypes, with the highest CLBR observed in patients with phenotype A/HOP (= hyperandrogenism + ovulatory disorder + polycystic ovaries), while IVM in patients with phenotype C/HP (hyperandrogenism + polycystic ovaries) or D/OP (ovulatory disorder + polycystic ovaries) resulted in lower CLBRs (OR 0.26 (CI 0.06-1.05) and OR 0.47 (CI 0.25-0.88), respectively, P = 0.03). WHAT IS KNOWN ALREADY: CLBRs in women with hyperandrogenic PCOS phenotypes (A/HOP and C/HP) have been reported to be lower after ovarian stimulation (OS) and ART when compared to CLBR in women with a normo-androgenic PCOS phenotype (D/OP) and non-PCOS patients with a PCO-like ovarian morphology (PCOM). Whether there is an influence of the different PCOS phenotypes on success rates of IVM has been unknown. STUDY DESIGN, SIZE, DURATION: This was a single-centre, retrospective cohort study including 320 unique PCOS patients performing their first IVM cycle between April 2014 and January 2018 in a tertiary referral hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS: Baseline patient characteristics and IVM treatment cycle data were collected. The clinical outcomes following the first IVM embryo transfer were retrieved, including the CLBR defined as the number of deliveries with at least one live birth resulting from one IVM cycle and all appended cycles in which fresh or frozen embryos were transferred until a live birth occurred or until all embryos were used. The latter was considered as the primary outcome. A multivariate regression model was developed to identify prognostic factors for CLBR and test the impact of the patient's PCOS phenotype. MAIN RESULTS AND THE ROLE OF CHANCE: Half of the patients presented with a hyperandrogenic PCOS phenotype (n = 140 A/HOP and n = 20 C/HP vs. n = 160 D/OP). BMI was significantly different between phenotype groups (27.4 ± 5.4 kg/m2 for A/HOP, 27.1 ± 5.4 kg/m2 for C/HP and 23.3 ± 4.4 kg/m2 for D/OP, P < 0.001). Metformin was used in 33.6% of patients with PCOS phenotype A/HOP, in 15.0% of C/HP patients and in 11.2% of D/OP patients (P < 0.001). Anti-müllerian hormone levels differed significantly between groups: 12.4 ± 8.3 µg/l in A/HOP, 7.7 ± 3.1 µg/l in C/HP and 10.4 ± 5.9 µg/l in D/OP patients (P = 0.01). The number of cumulus-oocyte complexes (COC) was significantly different between phenotype groups: 25.9 ± 19.1 COC in patients with phenotype A/HOP, 18.3 ± 9.0 COC in C/HP and 19.8 ± 13.5 COC in D/OP (P = 0.004). After IVM, patients with different phenotypes also had a significantly different number of mature oocytes (12.4 ± 9.3 for A/HOP vs. 6.5 ± 4.2 for C/HP vs. 9.1 ± 6.9 for D/OP, P < 0.001). The fertilisation rate, the number of usable embryos and the number of cycles with no embryo available for transfer were comparable between the three groups. Following the first embryo transfer, the positive hCG rate and LBR were comparable between the patient groups (44.7% (55/123) for A/HOP, 40.0% (6/15) for C/HP, 36.7% (47/128) for D/OP, P = 0.56 and 25.2% (31/123) for A/HOP, 6.2% (1/15) for C/HP, 26.6% (34/128) for D/OP, respectively, P = 0.22). However, the incidence of early pregnancy loss was significantly different across phenotype groups (19.5% (24/123) for A/HOP, 26.7% (4/15) for C/HP and 10.2% (13/128) for D/OP, P = 0.04). The CLBR was not significantly different following univariate analysis (40.0% (56/140) for A/HOP, 15% (3/20) for C/HP and 33.1% (53/160) for D/OP (P = 0.07)). When a multivariable logistic regression model was developed to account for confounding factors, the PCOS phenotype appeared to be significantly correlated with CLBR, with a more favourable CLBR in the A/HOP subgroup (OR 0.26 for phenotype C/HP (CI 0.06-1.05) and OR 0.47 for phenotype D/OP (CI 0.25-0.88), P = 0.03)). LIMITATIONS, REASONS FOR CAUTION: These data should be interpreted with caution as the retrospective nature of the study holds the possibility of unmeasured confounding factors and misassignment of the PCOS phenotype. Moreover, the sample size for phenotype C/HP was too small to draw conclusions for this subgroup of patients. WIDER IMPLICATIONS OF THE FINDINGS: Caucasian infertile patients with a PCOS phenotype A/HOP who undergo IVM achieved a higher CLBR than their counterparts with C/HP and D/OP. This is in strong contrast with previously reported outcomes following OS where women with PCOS and hyperandrogenism (A/HOP and C/HP) performed significantly worse. For PCOS patients who require ART, the strategy of OS followed by an elective freeze-all strategy remains to be compared with IVM in a prospective fashion; however, the current data provide support for IVM as a valid treatment option, especially in the most severe PCOS phenotypes (A/HOP). Our data suggest that proper patient selection is of utmost importance in an IVM programme. STUDY FUNDING/COMPETING INTEREST(S): The clinical IVM research has been supported by research grants from Cook Medical and Besins Healthcare. All authors declared no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

ESHRE Clinical Embryologist certification: the first 10 years.

STUDY QUESTION: What has the ESHRE programme 'ESHRE Certification for Clinical Embryologists' achieved after 10 years? SUMMARY ANSWER: The post-exam analysis showed a pass rate of 60% for Clinical and 50% for Senior Clinical Embryologists and a high level of internal consistency of all exams, leading to a total of 773 certified Clinical and 493 Senior Clinical Embryologists over the decade. WHAT IS KNOWN ALREADY: In an ESHRE survey on the educational and professional status of Clinical Embryology in Europe, it was found that education of laboratory personnel working in the field of assisted reproduction is highly variable between countries. In 2008, ESHRE introduced a programme, curriculum and certification in the field of Clinical Embryology. Knowledge gained by postgraduate study of recommended literature, following a clear curriculum, is verified by a written two-level exam for obtaining a certificate for Clinical (basic) or Senior Clinical (advanced) Embryologists. With a total of 1266 certificates awarded over a period of 10 years and recognition by the Union Européenne des Médecins Spécialistes and their Council for European Specialists Medical Assessment, the ESHRE Clinical Embryology exams have become an internationally recognized educational standard in the field of Clinical Embryology. STUDY DESIGN SIZE DURATION: A retrospective analysis of all applications for ESHRE Clinical (2009-2018) and Senior Clinical Embryologist Certification (2008-2018) and exam results of the first decade was carried out by the Steering Committee for Clinical Embryologist Certification. PARTICIPANTS/MATERIALS SETTING METHODS: A total of 2894 applications for ESHRE Certification for Clinical Embryologists and the results of 10 exams for the Clinical (1478 candidates) and 11 exams for Senior Clinical (987 candidates) levels were analysed. A detailed post-exam retrospective analysis was performed regarding difficulty, discrimination and reliability levels of 1600 multiple-choice questions (MCQs) with a single best answer among four options, from eight different curriculum topics (Basic cell biology, Genetics, Developmental biology, Female reproduction, Male reproduction, IVF laboratory, Cryopreservation and Laboratory management), representing the core theoretical knowledge of Clinical Embryology. Difficulty levels of the MCQs were subsequently compared regarding each topic and each yearly exam. The participation and success rates in the ESHRE Clinical Embryology exams were also assessed in terms of the educational and geographic backgrounds of candidates. MAIN RESULTS AND THE ROLE OF CHANCE: Over the 10 years studied, the mean pass rate for the Clinical Embryologist exam was 60% (range 41-86%), and for the Senior Clinical Embryologist exam was 50% (range 34-81%). On average, 63% European candidates and 35% non-European candidates passed the Clinical Embryologist exam, while 52% European candidates and 31% non-European candidates passed the Senior Clinical Embryologist exam. The candidates' educational level impacted on the success of the Clinical Embryologist exam but not of the Senior Clinical Embryologist exam. The mean difficulty indices by study topic showed that in the period of 10 years, there were no statistically significant differences between topics, for either the Clinical or Senior Clinical Embryologist exams. However, the overall exam difficulty varied between years. Reassuringly, the exam MCQ discrimination and reliability indices always showed a high level of internal consistency in all exams. LIMITATIONS REASONS FOR CAUTION: Some data from the initial ESHRE certification programme were not obtained electronically, in particular data for education, implying tables and figures reflect the specified valid data periods. Several countries exhibit different study profiles for those working in ART laboratories, such that laboratory technicians/technologists predominate in some countries, while in others only biologists and medical doctors are allowed to work with human embryos. Such differences could consequently affect the exam performance of candidates from specific countries. WIDER IMPLICATIONS OF THE FINDINGS: The ESHRE exams on Clinical Embryology are the most widely, internationally accepted tests of knowledge in the rapidly growing area of human reproduction. Clinical Embryology is increasingly recognized as a specific discipline for scientific staff who are collaborating closely with clinicians in managing human infertility through medically assisted reproduction. The analysis of the first 10 years of application of a two-level exam for Clinical Embryology shows a consistent high quality and reliability of the exam and MCQs used. These results represent an important follow-up of the quality of the ESHRE Certification programme for Clinical Embryologists, and convincingly position Clinical Embryology in the wider group of health disciplines that are harmonized through professional bodies such as ESHRE and European Board & College of Obstetrics and Gynaecology. The exams provide a clear step towards the increasing professional recognition and establishment of Clinical Embryology within health systems at both European and international level. STUDY FUNDING/COMPETING INTERESTS: No competing interest. All costs of the Steering Committee meetings were covered by ESHRE.

Live births following fertility preservation using in-vitro maturation of ovarian tissue oocytes.

STUDY QUESTION: Can oocytes extracted from excised ovarian tissue and matured in vitro be a useful adjunct for urgent fertility preservation (FP)? SUMMARY ANSWER: Ovarian tissue oocyte in-vitro maturation (OTO-IVM) in combination with ovarian tissue cryopreservation (OTC) is a valuable adjunct technique for FP. WHAT IS KNOWN ALREADY: Despite the impressive progress in the field, options for FP for cancer patients are still limited and, depending on the technique, clinical outcome data are still scarce. STUDY DESIGN, SIZE, DURATION: This was a retrospective cohort study conducted at a university hospital-affiliated fertility clinic between January 2012 and May 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study included 77 patients who underwent unilateral oophorectomy for OTC. Cumulus-oocyte complexes (COCs) obtained during ovarian tissue processing were matured in vitro for 28-42 h. Oocytes reaching metaphase II stage were vitrified or inseminated for embryo vitrification. MAIN RESULTS AND THE ROLE OF CHANCE: Overall, 1220 COCs were collected. The mean oocyte maturation rate was 39% ± 23% (SD). There were 64 patients who had vitrification of oocytes (6.7 ± 6.3 oocytes per patient). There were 13 patients who had ICSI of mature oocytes after IVM, with 2.0 ± 2.0 embryos vitrified per patient. Twelve patients have returned to the clinic with a desire for pregnancy. For seven of these, OTO-IVM material was thawed. Two patients had OTO-IVM oocytes warmed, with survival rates of 86% and 60%. After ICSI, six oocytes were fertilised in total, generating three good quality embryos for transfer, leading to a healthy live birth for one patient. In five patients, for whom a mean of 2.0 ± 0.8 (SD) embryos had been vitrified, seven embryos were warmed in total: one embryo did not survive the warming process; two tested genetically unsuitable for transfer; and four were transferred in separate cycles to three different patients, resulting in two healthy babies. In this small series, the live birth rate per patient after OTO-IVM, ICSI and embryo transfer was 43%. LIMITATIONS, REASONS FOR CAUTION: The retrospective study design and the limited sample size should be considered when interpreting results. WIDER IMPLICATIONS OF THE FINDINGS: The results of the study illustrate the added value of OTO-IVM in combination with OTC. We report the first live birth following the use of this appended technique combined with oocyte vitrification. STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for this study. M.D.V. reports honoraria for lectures in the last 2 years from MSD and Ferring, outside the submitted work, as well as grant support from MSD. The other authors have nothing to declare. TRIAL REGISTRATION NUMBER: N/A.

Birthweight of singletons born after blastocyst-stage or cleavage-stage transfer: analysis of a data set from three randomized controlled trials.

PURPOSE: The present post hoc analysis aims to study the neonatal data of singletons born from three randomized controlled trials (RCTs) which compared the outcome of day 3 and day 5 transfers. METHODS: Our analysis included 208 liveborn singletons from three existing RCTs (publication dates 2004, 2005, and 2006), 93 children from cleavage-stage transfers and 115 from blastocyst-stage transfers. Vanishing twins were excluded from the analysis. Singleton birthweight was the primary outcome measure. Gestational age and gender of the newborn were accounted for in the multiple regression analysis, along with other confounding factors, such as maternal age, BMI, parity, and smoking behavior. RESULTS: There was no significant difference in gestational age (median, interquartile range) between cleavage-stage transfer (275 days; 267-281) and blastocyst-stage transfer (277 days; 270-281; p = 0.22). Singleton birthweight (median, interquartile range) was not significantly different between cleavage-stage transfer (3330 g; 3020-3610) and blastocyst-stage transfer (3236 g; 2930-3630; p = 0.40), even following multivariable regression analysis to control for potential maternal and newborn confounders. CONCLUSION: The gestational age and birthweight were not significantly different after cleavage-stage and blastocyst-stage transfers. One limitation to be recognized is the age of the data, with original data collection dates from 2001 to 2004. Additionally, the RCTs used for the present analysis have a fairly young age restriction.

Oocyte donation in donors with levonorgestrel intrauterine device: a good match?

RESEARCH QUESTION: Does the levonorgestrel-releasing intrauterine device (LNG-IUD) influence cumulative live birth rate (CLBR) in oocyte donor cycles? DESIGN: Retrospective cohort study based on prospectively collected data from 1 May 2009 to 31 December 2017, without attrition, consisting of 491 consecutive cycles of vitrified oocyte donation, none lost to follow-up (unique donor-recipient pairs). All donors underwent ovarian stimulation using gonadotrophin releasing hormone (GnRH) antagonist co-treatment and GnRH agonist trigger. CLBR was chosen as primary outcome measure. RESULTS: In total, 103 (21.0%) cycles were carried out in donors carrying a LNG-IUD. In 388 (79.0%) cycles, no LNG-IUD was present. After confounder-adjustment, the use of an LNG-IUD did not have a statistically significant influence on CLBR. CONCLUSIONS: The LNG-IUD does not negatively affect CLBR.

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.