Effects of first and second division modes on euploidy acquisition in human embryo

The aim of this study was to non-invasively investigate euploid embryos using methods other than pre-implantation genetic testing for aneuploidy. The study focused on direct cleavage (DC) observed during early embryo development. We also investigated the relationship between the mode of early embryo division and embryo ploidy. Embryos were divided into the normal cleavage (NC) and DC groups, and the DC group was further subdivided into the DC-First (DC-F) and DC-Second (DC-S) groups, depending on whether DC was observed at the first or second cleavage, respectively. The acquisition rates of euploid embryos and embryos appropriate for transfer were compared between the groups. Our results revealed that the timing of the first division did not differ between blastocyst grades or in embryos with varying degrees of ploidy. Further, the timing of the first cleavage did not affect the acquisition rate of embryos appropriate for transfer and euploid embryo formation rate did not significantly differ between the DC and NC groups. We also noted that for embryos appropriate for transfer, euploidy acquisition rate did not differ significantly between the DC and NC groups. Further, the euploidy acquisition rate of embryos did not differ between the DC-F and DC-S groups. However, the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group. These findings indicated that the number of good-quality blastocysts formed was significantly higher in the NC group than in the DC group and the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group.

Formation of the first plane of division relative to the pronuclear axis predicts embryonic ploidy

RESEARCH QUESTION

Is there a relationship between the pronuclear axis and the first cleavage plane formation in human pronuclear-stage embryos, and what are the effects on ploidy and clinical pregnancy rates?

DESIGN

Transferred embryos were followed up until their prognoses. A total of 762 embryos formed two cells and reached the blastocyst stage after normal fertilization in a time-lapse incubator. Embryos were classified into three groups: group A: embryos in which the first plane of division was formed parallel to the axis of the pronucleus; group B: embryos in which cases of oblique formation were observed; and group C: embryos in which cases of perpendicular formation were observed.

RESULTS

The euploidy rate was significantly higher in groups A and B than those in group C (P < 0.01), whereas the aneuploidy rate was significantly higher in group C (P < 0.01) than in groups A and B. No differences were found between the three groups in frequency of positive HCG-based pregnancy tests, frequency of clinical pregnancies, miscarriage rates or delivery rates.

CONCLUSIONS

The formation pattern of the first plane of division relative to the pronuclear axis was a predictor of embryonic ploidy, with a reduced rate of euploidy and a high probability of aneuploidy observed when the first plane of division was perpendicular to the pronuclear axis.

The ovarian stimulation regimen does not affect aneuploidy or blastocyst rate

RESEARCH QUESTION

Could the total dose (<3000 IU or ≥3000 IU) and type of exogenous gonadotrophin (i.e. recombinant FSH and/or human menopausal gonadotrophin [HMG]) influence aneuploidy and blastulation rates and produce different reproductive outcomes?

DESIGN

This retrospective, observational, multicentre cohort study included a total of 8466 patients undergoing IVF using autologous oocytes and preimplantation genetic testing for aneuploidies. Participants were divided according to the dosage of total gonadotrophins and stratified by maternal age.

RESULTS

The aneuploidy rates, pregnancy outcomes and cumulative live birth rates (CLBR) were similar among women who received total gonadotrophin dosages of <3000 or ≥3000 IU. No statistical differences were reported in the blastulation rate with lower or higher gonadotrophin dosages. Women receiving a higher amount of HMG during ovarian stimulation had a lower aneuploidy rate (P = 0.02); when stratified according to age, younger women with a higher HMG dosage had lower aneuploidy rates (P< 0.001), while no statistical differences were observed in older women with higher or lower HMG dosages. No significant differences were observed in IVF outcomes or CLBR.

CONCLUSIONS

High doses of gonadotrophins were not associated with rate of aneuploidy. However, an increased fraction of HMG in younger women was associated with a lower aneuploidy rate. The study demonstrated that the total gonadotrophin dosage did not influence aneuploidy, reproductive outcomes or CLBR. The increased gonadotrophin and HMG dosages used for ovarian stimulation did not precede aneuploidy, and the use of HMG should be evaluated on a case-by-case basis, according to the individual's characteristics and infertility type.

In Vitro Culture of Mammalian Embryos: Is There Room for Improvement?

Preimplantation embryo culture, pivotal in assisted reproductive technology (ART), has lagged in innovation compared to embryo selection advancements. This review examines the persisting gap between in vivo and in vitro embryo development, emphasizing the need for improved culture conditions. While in humans this gap is hardly estimated, animal models, particularly bovines, reveal clear disparities in developmental competence, cryotolerance, pregnancy and live birth rates between in vitro-produced (IVP) and in vivo-derived (IVD) embryos. Molecular analyses unveil distinct differences in morphology, metabolism, and genomic stability, underscoring the need for refining culture conditions for better ART outcomes. To this end, a deeper comprehension of oviduct physiology and embryo transport is crucial for grasping embryo-maternal interactions' mechanisms. Research on autocrine and paracrine factors, and extracellular vesicles in embryo-maternal tract interactions, elucidates vital communication networks for successful implantation and pregnancy. In vitro, confinement, and embryo density are key factors to boost embryo development. Advanced dynamic culture systems mimicking fluid mechanical stimulation in the oviduct, through vibration, tilting, and microfluidic methods, and the use of innovative softer substrates, hold promise for optimizing in vitro embryo development.

Development of a Novel Non-invasive Metabolomics Assay to Predict Implantation Potential of Human Embryos

Can a set of metabolites present in embryo culture media correlate with embryo implantation? Case-control study in two phases: discovery phase (101 samples) and validation phase (169 samples), collected between 2018 and 2022, with a total of 218 participants. Culture media samples with known implantation outcomes were collected after blastocyst embryo transfer (including both PGT and non-PGT cycles) and were analyzed using chromatography followed by mass spectrometry. The spectra were processed and analyzed using statistical and machine learning techniques to identify biomarkers associated with embryo implantation, and to develop a predictive model. In the discovery phase, 148 embryo implantation biomarkers were identified using high resolution equipment, and 47 of them were characterized. Our results indicate a significant enrichment of tryptophan metabolism, arginine and proline metabolism, and lysine degradation biochemical pathways. After transferring the method to a lower resolution equipment, a model able to assign a Metabolite Pregnancy Index (MPI) to each embryo culture media was developed, taking the concentration of 36 biomarkers as input. Applying this model to 20% of the validation samples (N=34) used as the test set, an accuracy of 85.29% was achieved, with a PPV (Positive Predictive Value) of 88% and a NPV (Negative Predictive Value) of 77.78%. Additionally, informative results were obtained for all the analyzed samples. Metabolite concentration in the media after in vitro culture shows correlation with embryo implantation potential. Furthermore, the mathematical combination of biomarker concentrations using Artificial Intelligence techniques can be used to predict embryo implantation outcome with an accuracy of around 85%.

The impact of (very) young donor age on euploid rates: An analysis of 1831 trophectoderm biopsies evaluated with 24-chromosome NGS screening in oocyte donation cycles

RESEARCH QUESTION

Conflicting data exists regarding whether a younger age of donors has a negative influence on the outcomes of oocyte donation cycles. Is there any correlation between a younger age of donors and the rate of embryonic aneuploidy in oocyte donation cycles?

DESIGN

Retrospective study including 515 oocyte donation cycles carried out between February 2017 and November 2022. Comprehensive chromosomal screening was performed on 1831 blastocysts. 1793 had a result which were categorised into groups based on the age of the donor: 18-22 (n = 415), 23-25 (n = 600), 26-30 (n = 488), and 31-35 years (n = 290). The analysis aimed to determine the percentage of biopsy samples that were euploid and the number that were aneuploid, relative to the age group of the oocyte donor. Additionally, linear regression was employed to examine the relationship between age and the proportion of aneuploid embryos, while controlling for relevant variables.

RESULTS

Aneuploidy increased predictably with donor age: 18-22 years: 27.5 %; 23-25 years: 31.2 %; 26-30 years: 31.8 %; and 31-35 years: 38.6 %. In the donor group aged 31-35 years, a higher percentage of aneuploid embryos was observed compared to younger donors in univariate analysis (OR: 1.66, 95 % CI: 1.21-2.29, p = 0.002) and multivariate logistic analysis (OR: 2.65, 95 % CI: 1.67-4.23, p < 0.001). The rates of embryonic mosaicism revealed no significant differences.

CONCLUSION

The lowest risk of embryonic aneuploidy was found among donors aged <22 years. Conversely, an elevated prevalence was evident within the donor group aged 31-35 years, in contrast to the younger cohorts. The incidence of mosaic embryos remained consistent across all age groups.

Assessment of the Role of Endometrial Receptivity Analysis in Enhancing Assisted Reproductive Technology Outcomes for Advanced-Age Patients

BACKGROUND AND OBJECTIVES

In contemporary society, socially active women are increasingly planning their fertility for later in life. The fertility outcomes for advanced-age patients, even with egg donation, are often suboptimal due to endometrial aging. Recurrent implantation failure (RIF) is one of the core problems for assisted reproductive technology (ART), especially for advanced-age patients. High-quality, euploid embryos and synchronization between the embryonic stage and the uterine endometrial lining are crucial for positive outcomes. The study aims to improve ART outcomes with personalized embryo transfer (pET) according to endometrial receptivity analysis (ERA) in advanced-age patients with challenging reproductive histories, and RIF by utilizing, donor oocytes and preimplantation genetic testing for aneuploidy (PGT-A) for embryo testing.

METHODS

A randomized, controlled observational follow-up study was conducted from 2020 to 2023. After obtaining informed consent, 320 patients with RIF were selected. Patients were allocated into the study group and control group 1 based on consistent application of randomization principles, while control group 2 was selected separately. The study group included patients undergoing PGT-A and ERA, aged 35-45 years, with a mean age of 40.5±3.7 years. Control group 1 comprised patients undergoing PGT-A, aged 35-45 years, with a mean age of 40±4.2 years. Control group 2 consisted of patients undergoing PGT-A and ERA, aged less than 35 years, with a mean age of 31.6±2.2 years.

RESULTS

Results suggest that ERA may improve implantation and pregnancy outcomes in advanced-age patients, particularly those with RIFs. The pregnancy rate was significantly higher in the study group (77.9%), compared to control group 1 (57.6%) (p=0.0007), and no significant difference compared to control group 2 (77.3%) (p=0.94). The implantation rate was higher in the study group (54.1%) than in control group 1 (39.4%) (p=0.0009), and there was no significant difference between the study group and control group 2 (50%, p=0.87). The live birth rate was also higher in the study group (71.3%), compared to control group 1 (39.4%) (p<0.0001). There were no significant differences between the study group and control group 2 (65.9%, p=0.50).

CONCLUSION

pET guided by ERA significantly improves pregnancy, implantation, and live birth rates in advanced-age patients with challenging reproductive histories. pET provides ART outcomes with no significant difference between advanced-age patients and younger patients with pET guided by ERA.

Intrauterine Infusion and Hysteroscopic Injection of Autologous Platelet-Rich Plasma for Patients with a Persistent Thin Endometrium: A Prospective Case-Control Study

Objectives: To evaluate the effect of intrauterine infusion and hysteroscopic injection of autologous platelet-rich plasma (PRP) in patients with a persistent thin endometrium (EM) undergoing euploid frozen embryo transfer (EFET) cycles. Methods: This prospective case-control study enrolled 116 infertile women with thin EM (<7 mm) who underwent hormone replacement therapy (HRT) for EFET. These women had experienced at least one previous unsuccessful EFET cycle, which either resulted in the cancellation of the cycle or failure of pregnancy. A total of 55 women received an intrauterine infusion of PRP before FET, 38 received a hysteroscopic injection of PRP, and 23 received standard HRT treatment without PRP (control group). Only euploid embryos were transferred in these cycles. The primary outcomes were the implantation rate (IR) and clinical pregnancy rate (CPR) after EFET. Results: After receiving intrauterine infusion and hysteroscopic injection of PRP, 78.2% and 55.3% of patients, respectively, showed an EM thickness exceeding 7 mm, followed by embryo transfer. The hysteroscopic injection group demonstrated significantly higher IR (52%), a higher trend of CPR (52%), and a higher live birth rate (38%) than the control group (18%, 22%, and 4%). Conclusions: Intrauterine infusion and hysteroscopic injection of autologous PRP may be effective methods to increase EM thickness in HRT cycles. According to our results, both methods could increase EM thickness, while hysteroscopic injection appeared to provide more significant assistance in increasing IR, CPR, and live birth rate after EFET in patients with persistent thin EM.

Appropriate whole genome amplification and pathogenic loci detection can improve the accuracy of preimplantation genetic diagnosis for deletional α-thalassemia

Objective

To improve the accuracy of preimplantation genetic testing (PGT) in deletional α-thalassemia patients.

Design

Article.

Patients

fifty-two deletional α-thalassemia couples.

Interventions

Whole genome amplification (WGA), Next-generation sequencing (NGS) and PCR mutation loci detection.

Main outcome measures

WGA, Single nucleotide polymorphism (SNP) and PCR mutation loci detection results; Analysis of embryo chromosome copy number variation (CNV).

Results

Multiple Displacement Amplification (MDA) and Multiple Annealing and Looping-Based Amplification Cycles (MALBAC) methods for PGT for deletional α-thalassemia. Blastocyst biopsy samples (n = 253) were obtained from 52 deletional α-thalassemia couples. The results of the comparison of experimental data between groups MALBAC and MDA are as follows: (i) The average allele drop-out (ADO) rate, MALBAC vs. MDA = 2.27% ± 3.57% vs. 0.97% ± 1.4%, P=0.451); (ii) WGA success rate, MALBAC vs. MDA = 98.61% vs. 98.89%, P=0.851; (iii) SNP haplotype success rate, MALBAC vs. MDA = 94.44% vs. 96.68%, P=0.409; (iv) The result of SNP haplotype analysis is consistent with that of Gap-PCR/Sanger sequencing results, MALBAC vs. MDA = 36(36/72, 50%) vs. 151(151/181, 83.43%), P=0; (v) Valid SNP loci, MALBAC vs. MDA = 30 ± 9 vs. 34 ± 10, P=0.02; (vi) The mean CV values, MALBAC vs. MDA = 0.12 ± 0.263 vs. 0.09 ± 0.40, P=0.916; (vii) The average number of raw reads, MALBAC vs. MDA =3244259 ± 999124 vs. 3713146 ± 1028721, P=0; (viii) The coverage of genome (%), MALBAC vs. MDA = 5.02 ± 1.09 vs. 5.55 ± 1.49, P=0.008.

Conclusions

Our findings indicate that MDA is superior to MALBAC for PGT of deletional α-thalassemia. Furthermore, SNP haplotype analysis combined with PCR loci detection can improve the accuracy and detection rate of deletional α-thalassemia.

Preimplantation Genetic Testing for Polygenetic Conditions: A Legal, Ethical, and Scientific Challenge

The recent commercialization of the Embryo Health Score (EHS), determined through preimplantation genetic testing for polygenic conditions, offers the potential to select embryos with lower disease risk, thus potentially enhancing offspring longevity and health. Lately, Orchid Health company increased testing from less than 20 diseases to more than 900+ conditions for birth defects. However, the "geneticization" of phenotype estimates to a health state erases the environmental part, including the in vitro fertilization potential risks, questioning its scientific usefulness. EHS is utilized in countries with minimal regulatory oversight and will likely expand, while it remains illegal in other countries due to ethical and legal dilemmas it raises about reproductive autonomy, discrimination, impacts on family dynamics, and genetic diversity. The shift toward commercialized polygenic embryo screening (PES) redefines healthcare relationships, turning prospective parents into consumers and altering the physician's role. Moreover, PES could increase social inequalities, stigmatize those not born following PES, and encourage "desirable" phenotypic or behavioral traits selection, leading to ethical drift. Addressing these issues is essential before further implementation and requires a collaborative approach involving political, governmental, and public health, alongside geneticists, ethicists, and fertility specialists, focusing on the societal implications and acceptability of testing for polygenic traits for embryo selection.

Implicit bias in diagnosing mosaicism amongst preimplantation genetic testing providers: results from a multicenter study of 36 395 blastocysts

STUDY QUESTION

Does the diagnosis of mosaicism affect ploidy rates across different providers offering preimplantation genetic testing for aneuploidies (PGT-A)?

SUMMARY ANSWER

Our analysis of 36 395 blastocyst biopsies across eight genetic testing laboratories revealed that euploidy rates were significantly higher in providers reporting low rates of mosaicism.

WHAT IS KNOWN ALREADY

Diagnoses consistent with chromosomal mosaicism have emerged as a third category of possible embryo ploidy outcomes following PGT-A. However, in the era of mosaicism, embryo selection has become increasingly complex. Biological, technical, analytical, and clinical complexities in interpreting such results have led to substantial variability in mosaicism rates across PGT-A providers and clinics. Critically, it remains unknown whether these differences impact the number of euploid embryos available for transfer. Ultimately, this may significantly affect clinical outcomes, with important implications for PGT-A patients.

STUDY DESIGN, SIZE, DURATION

In this international, multicenter cohort study, we reviewed 36 395 consecutive PGT-A results, obtained from 10 035 patients across 11 867 treatment cycles, conducted between October 2015 and October 2021. A total of 17 IVF centers, across eight PGT-A providers, five countries and three continents participated in the study. All blastocysts were tested using trophectoderm biopsy and next-generation sequencing. Both autologous and donation cycles were assessed. Cycles using preimplantation genetic testing for structural rearrangements were excluded from the analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The PGT-A providers were randomly categorized (A to H). Providers B, C, D, E, F, G, and H all reported mosaicism, whereas Provider A reported embryos as either euploid or aneuploid. Ploidy rates were analyzed using multilevel mixed linear regression. Analyses were adjusted for maternal age, paternal age, oocyte source, number of embryos biopsied, day of biopsy, and PGT-A provider, as appropriate. We compared associations between genetic testing providers and PGT-A outcomes, including the number of chromosomally normal (euploid) embryos determined to be suitable for transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean maternal age (±SD) across all providers was 36.2 (±5.2). Our findings reveal a strong association between PGT-A provider and the diagnosis of euploidy and mosaicism. Amongst the seven providers that reported mosaicism, the rates varied from 3.1% to 25.0%. After adjusting for confounders, we observed a significant difference in the likelihood of diagnosing mosaicism across providers (P < 0.001), ranging from 6.5% (95% CI: 5.2-7.4%) for Provider B to 35.6% (95% CI: 32.6-38.7%) for Provider E. Notably, adjusted euploidy rates were highest for providers that reported the lowest rates of mosaicism (Provider B: euploidy, 55.7% (95% CI: 54.1-57.4%), mosaicism, 6.5% (95% CI: 5.2-7.4%); Provider H: euploidy, 44.5% (95% CI: 43.6-45.4%), mosaicism, 9.9% (95% CI: 9.2-10.6%)); and Provider D: euploidy, 43.8% (95% CI: 39.2-48.4%), mosaicism, 11.0% (95% CI: 7.5-14.5%)). Moreover, the overall chance of having at least one euploid blastocyst available for transfer was significantly higher when mosaicism was not reported, when we compared Provider A to all other providers (OR = 1.30, 95% CI: 1.13-1.50). Differences in diagnosing and interpreting mosaic results across PGT-A laboratories raise further concerns regarding the accuracy and relevance of mosaicism predictions. While we confirmed equivalent clinical outcomes following the transfer of mosaic and euploid blastocysts, we found that a significant proportion of mosaic embryos are not used for IVF treatment.

LIMITATIONS, REASONS FOR CAUTION

Due to the retrospective nature of the study, associations can be ascertained, however, causality cannot be established. Certain parameters such as blastocyst grade were not available in the dataset. Furthermore, certain platform-related and clinic-specific factors may not be readily quantifiable or explicitly captured in our dataset. As such, a full elucidation of all potential confounders accounting for variability may not be possible.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings highlight the strong need for standardization and quality assurance in the industry. The decision not to transfer mosaic embryos may ultimately reduce the chance of success of a PGT-A cycle by limiting the pool of available embryos. Until we can be certain that mosaic diagnoses accurately reflect biological variability, reporting mosaicism warrants utmost caution. A prudent approach is imperative, as it may determine the difference between success or failure for some patients.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Torres Quevedo Grant, awarded to M.P. (PTQ2019-010494) by the Spanish State Research Agency, Ministry of Science and Innovation, Spain. M.P., L.B., A.R.L., A.L.R.d.C.L., N.P.P., M.P., D.S., F.A., A.P., B.M., L.D., F.V.M., D.S., M.R., E.P.d.l.B., A.R., and R.V. have no competing interests to declare. B.L., R.M., and J.A.O. are full time employees of IB Biotech, the genetics company of the Instituto Bernabeu group, which performs preimplantation genetic testing. M.G. is a full time employee of Novagen, the genetics company of Cegyr, which performs preimplantation genetic testing.

TRIAL REGISTRATION NUMBER

N/A.

Oocyte rescue in-vitro maturation does not adversely affect chromosome segregation during the first meiotic division

RESEARCH QUESTION

Does rescue in-vitro maturation (IVM) in the presence or absence of cumulus cells, affect the progress of meiosis I, compared with oocytes that mature in vivo?

DESIGN

This prospective study was conducted in a university-affiliated fertility centre. Ninety-five young oocyte donors (mean age 25.57 ± 4.47) with a normal karyotype and no known fertility problems were included. A total of 390 oocytes (116 mature metaphase II [MII] and 274 immature oocytes) were analysed. The immature oocytes underwent rescue IVM in the presence of cumulus cells (CC; IVM+CC; n = 137) or without them (IVM-CC; n = 137), and IVM rate was calculated. Chromosome copy number analysis using next-generation sequencing (NGS) was performed on all rescue IVM oocytes reaching MII as well as those that were mature at the time of initial denudation (in-vivo-matured oocytes [IVO]).

RESULTS

Maturation rates were similar in IVM+CC and IVM-CC oocytes (62.8 versus 71.5%, P = 0.16). Conclusive cytogenetic results were obtained from 65 MII oocytes from the IVM+CC group, 87 from the IVM-CC group, and 99 from the IVO group. Oocyte euploidy rates for the three groups were similar, at 75.4%, 83.9% and 80.8%, respectively (P = 0.42).

CONCLUSIONS

The results suggest that culture of germinal vesicle and metaphase I oocytes in the presence of cumulus cells does not improve rates of IVM. In general, the process of rescue IVM does not appear to alter the frequency of oocytes with a normal chromosome copy number.

Correlation between controlled ovarian stimulation protocols and euploid blastocyst rate in pre-implantation genetic testing for aneuploidy cycles

BACKGROUND

Several studies have explored which COS protocol yields a higher blastocyst euploidy rate, but findings have been inconsistent. The present study aimed to explore whether controlled ovarian stimulation (COS) protocols was associated with euploid blastocyst rate in pre-implantation genetic testing for aneuploidy (PGT-A) cycles.

METHODS

The study was a retrospective study where data were obtained from three reproductive medicine centers. The study included PGT-A cycles with the GnRH-a, GnRH-ant, or PPOS protocols, and the data on patient demographics, protocols, and embryonic outcomes were collected for the PGT-A cycles performed between January 2019 and August 2022.

RESULTS

This study included 457 PGT-A cycles from three reproductive medicine centers, with 152, 126, and 179 cycles performed using the PPOS, GnRH-a, and GnRH-ant protocols, respectively. The baseline characteristics of the three groups show no significant differences were observed in female BMI, infertility type, and infertility duration among the PPOS, GnRH-a, and GnRH-ant protocol groups. The study found no significant association between Gn dosage, Gn duration, and blastocyst euploidy. The mean number of euploidy blastocysts in PPOS protocol was significantly lower than that of GnRH-a protocol and GnRH-ant protocol (0.75 ± 0.92 vs. 1.79 ± 1.78 vs. 1.80 ± 1.67). The euploidy rate per biopsy blastocyst (48.4% vs. 49.1% vs. 33.1%), per oocyte retrieved (15.0% vs. 14.7% vs. 10.5%), and per MII oocyte (17.7% vs. 16.4% vs. 11.7%) were significantly higher in the cycles using the GnRH-ant and GnRH-a protocols than that of PPOS protocol group. Regression analyses indicated that, compared with the PPOS protocol, the GnRH-ant protocol was positively associated with the euploid blastocyst rate and the mean number of euploid blastocysts, whereas the GnRH-a protocol showed no such relationship.

LIMITATIONS AND REASONS FOR CAUTION

The main limitation of this study was the retrospective design. Although this study also used other tests to account for confounding factors and reduce potential bias, multiple tests have its own weaknesses.

CONCLUSIONS

GnRH-ant protocol was the most effective for PGT-A cycles. The findings emphasize the need for personalized treatment strategies, considering patient demographics, and optimizing COS protocols to enhance the chances of successful outcomes in ART procedures.

Good practice recommendations on add-ons in reproductive medicine†

STUDY QUESTION

Which add-ons are safe and effective to be used in ART treatment?

SUMMARY ANSWER

Forty-two recommendations were formulated on the use of add-ons in the diagnosis of fertility problems, the IVF laboratory and clinical management of IVF treatment.

WHAT IS KNOWN ALREADY

The innovative nature of ART combined with the extremely high motivation of the patients has opened the door to the wide application of what has become known as 'add-ons' in reproductive medicine. These supplementary options are available to patients in addition to standard fertility procedures, typically incurring an additional cost. A diverse array of supplementary options is made available, encompassing tests, drugs, equipment, complementary or alternative therapies, laboratory procedures, and surgical interventions. These options share the common aim of stating to enhance pregnancy or live birth rates, mitigate the risk of miscarriage, or expedite the time to achieving pregnancy.

STUDY DESIGN, SIZE, DURATION

ESHRE aimed to develop clinically relevant and evidence-based recommendations focusing on the safety and efficacy of add-ons currently used in fertility procedures in order to improve the quality of care for patients with infertility.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ESHRE appointed a European multidisciplinary working group consisting of practising clinicians, embryologists, and researchers who have demonstrated leadership and expertise in the care and research of infertility. Patient representatives were included in the working group. To ensure that the guidelines are evidence-based, the literature identified from a systematic search was reviewed and critically appraised. In the absence of any clear scientific evidence, recommendations were based on the professional experience and consensus of the working group. The guidelines are thus based on the best available evidence and expert agreement. Prior to publication, the guidelines were reviewed by 46 independent international reviewers. A total of 272 comments were received and incorporated where relevant.

MAIN RESULTS AND THE ROLE OF CHANCE

The multidisciplinary working group formulated 42 recommendations in three sections; diagnosis and diagnostic tests, laboratory tests and interventions, and clinical management.

LIMITATIONS, REASONS FOR CAUTION

Of the 42 recommendations, none could be based on high-quality evidence and only four could be based on moderate-quality evidence, implicating that 95% of the recommendations are supported only by low-quality randomized controlled trials, observational data, professional experience, or consensus of the development group.

WIDER IMPLICATIONS OF THE FINDINGS

These guidelines offer valuable direction for healthcare professionals who are responsible for the care of patients undergoing ART treatment for infertility. Their purpose is to promote safe and effective ART treatment, enabling patients to make informed decisions based on realistic expectations. The guidelines aim to ensure that patients are fully informed about the various treatment options available to them and the likelihood of any additional treatment or test to improve the chance of achieving a live birth.

STUDY FUNDING/COMPETING INTEREST(S)

All costs relating to the development process were covered from ESHRE funds. There was no external funding of the development process or manuscript production. K.L. reports speakers fees from Merck and was part of a research study by Vitrolife (unpaid). T.E. reports consulting fees from Gynemed, speakers fees from Gynemed and is part of the scientific advisory board of Hamilton Thorne. N.P.P. reports grants from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare, speakers fees from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare. S.R.H. declares being managing director of Fertility Europe, a not-for-profit organization receiving financial support from ESHRE. I.S. is a scientific advisor for and has stock options from Alife Health, is co-founder of IVFvision LTD (unpaid) and received speakers' fee from the 2023 ART Young Leader Prestige workshop in China. A.P. reports grants from Gedeon Richter, Ferring Pharmaceuticals and Merck A/S, consulting fees from Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos and Merck A/S, speakers fees from Gedeon Richter, Ferring Pharmaceuticals, Merck A/S, Theramex and Organon, travel fees from Gedeon Richter. The other authors disclosed no conflicts of interest.

DISCLAIMER

This Good Practice Recommendations (GPRs) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation.ESHRE GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or bedeemedinclusive of all proper methods of care, or be exclusive of other methods of care reasonably directed to obtaining the same results.Theydo not replace the need for application of clinical judgement to each individual presentation, or variations based on locality and facility type.Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring, of any of the included technologies by ESHRE.

Evaluation of pre-implantation genetic testing for aneuploidy outcomes in patients without infertility undergoing in vitro fertilization compared to infertile controls

PURPOSE

To evaluate pre-implantation genetic testing for aneuploidy (PGT-A) outcomes in patients without infertility compared to infertile patients.

METHODS

We performed a retrospective cohort study of all patients without an infertility diagnosis ("fertile" patients) who utilized PGT-A at a large university-affiliated fertility center between 2016 and 2021. Fertile patients were 1-to-3 matched to infertile controls by age and number of oocytes retrieved. The primary outcome was blastocyst aneuploidy rate. Secondary outcomes included ovarian reserve markers, laboratory outcomes, and other PGT-A outcomes [rates of euploidy, mosaicism, and potentially transferrable (euploid + mosaic) embryos].

RESULTS

283 fertile and 849 infertile patients were included. Median age, anti-Mullerian hormone, and day 2 estradiol levels were equivalent among groups; day 2 follicle-stimulating hormone levels were higher in fertile patients (6.9 vs. 6.5 IU/mL, p < 0.01). The aneuploidy rate was similar among fertile and infertile patients (33.7% vs. 31.8%, p = 0.11); the euploidy rate was higher (50.8% vs. 47.0%, p < 0.01), and the mosaicism rate was lower in fertile patients (13.3% vs. 19.2%, p < 0.01). The rate of transferrable embryos was similar among groups (64.0% vs. 66.3%, p = 0.07), as was the percentage of patients yielding ≥ 1 euploid embryo (90.1% vs. 87.3%, p = 0.25). When controlling for significant covariates, multiple linear regression showed that aneuploidy rate was equivalent in both cohorts.

CONCLUSION

Aneuploidy rate was similar in fertile and infertile patients. Fertile patients had slightly higher euploidy and lower mosaicism than infertile patients. Still, compared to fertile patients, infertile patients had equivalent rates of transferrable embryos and were just as likely to yield ≥ 1 euploid embryo.

A novel embryo biopsy morphological analysis and genetic integrality criterion system significantly improves the outcome of preimplantation genetic testing

PURPOSE

While efforts have been made to establish blastocyst grading systems in the past decades, little research has examined the quality of biopsy specimens. This study is the first to correlate the morphology of biopsied trophectoderm (TE) cells to their quality and subsequent genetic testing results of preimplantation genetic testing (PGT), through an innovative Morphological Analysis and Genetic Integrality Criterion (MAGIC) system.

METHODS

Biopsied TE cells were first evaluated according to the MAGIC procedure, followed by whole-genome amplification (WGA) and library construction, and then sequenced using the Illumina X Ten Platform. Copy number variation (CNV) and allele drop-out (ADO) rates as well as test failure rates were compared and analyzed.

RESULTS

Our data explores the relationship between TE cell morphology and its quality and final genetic testing outcome, which is established based on the MAGIC system. MAGIC guarantees that only high- or good-quality TE cells are used for genetic testing to generate excellent data uniformity and lower ADO rates. Low-quality cells containing biopsied TE cell mass are responsible for the "background noise" of CNV analysis.

CONCLUSION

The MAGIC application has effectively decreased the false-positive mosaicism, hence to ensure the stability and veracity of detection results, to avoid misdiagnoses, and to improve accuracy, as well as to avoid re-biopsy procedures. The study also contributes to understand how the IVF laboratory and the molecular biology laboratory depend on each other to achieve good-quality PGT results, which are clinically relevant for the patients.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

Modification of peripheric Treg and CD56brightNK levels in RIF women after egg donation, treated with GM-CSF or placebo

Recurrent implantation failure (RIF) is defined as when implantation repeatedly failed to reach a stage recognizable by pelvic ultrasound in IVF cycle and it may be due to several causes. The GM-CSF is a cytokine promoting leukocyte growth and trophoblast development: we tested it to treat these patients in a pilot-controlled trial evaluating the modification of peripheric Treg and CD56brightNK levels after the treatment with this cytokine and in control patients affected by RIF after egg donation cycles. This study was performed on 24 RIF women after egg donation cycles. Single good quality blastocyst transfer was performed in the cycle object of this study. Patients were randomly assigned to two groups: 12 women treated with subcutaneous GM-CSF 0.3 mg/kg/daily from the day before embryo transfer to the β-hCG day, and 12 women treated with subcutaneous saline solution infusion as control. All patients were tested for Treg and CD56brightNK cell levels in blood circulation before and after treatment using flow-cytometry with specific antibodies. The two groups of patients were similar for epidemiologic characteristics, the ongoing pregnancy rate in the GM-CSF group was 83.3% whereas in the control group was 25.0% (P = 0.0123). In the study group there was a significative increase of Treg cells (P < 0.001) with respect to the levels before treatment and to control group. Instead, the levels of CD56brightNK did not show any significative variation. Our study showed that the treatment with GM-CSF increases the Treg cells in the peripheric blood.

Assessing the influence of distinct culture media on human pre-implantation development using single-embryo transcriptomics

The use of assisted reproductive technologies is consistently rising across the world. However, making an informed choice on which embryo culture medium should be preferred to ensure satisfactory pregnancy rates and the health of future children critically lacks scientific background. In particular, embryos within their first days of development are highly sensitive to their micro-environment, and it is unknown how their transcriptome adapts to different embryo culture compositions. Here, we determined the impact of culture media composition on gene expression in human pre-implantation embryos. By employing single-embryo RNA-sequencing after 2 or 5 days of the post-fertilization culture in different commercially available media (Ferticult, Global, and SSM), we revealed medium-specific differences in gene expression changes. Embryos cultured pre-compaction until day 2 in Ferticult or Global media notably displayed 266 differentially expressed genes, which were related to essential developmental pathways. Herein, 19 of them could have a key role in early development, based on their previously described dynamic expression changes across development. When embryos were cultured after day 2 in the same media considered more suitable because of its amino acid enrichment, 18 differentially expressed genes thought to be involved in the transition from early to later embryonic stages were identified. Overall, the differences were reduced at the blastocyst stage, highlighting the ability of embryos conceived in a suboptimal in vitro culture medium to mitigate the transcriptomic profile acquired under different pre-compaction environments.

Comparison of blastocyst euploidy rates following luteal versus follicular phase stimulation in a GnRH antagonist protocol: a prospective study with repeated ovarian stimulation cycles

STUDY QUESTION

Is there any difference in the mean number of euploid embryos following luteal phase start (LS) and follicular phase start (FS) of ovarian stimulation?

SUMMARY ANSWER

The mean number of euploid blastocysts is equivalent independent of whether the inseminated oocytes are derived from FS or LS.

WHAT IS KNOWN ALREADY

Starting ovarian stimulation at any time of the cycle ('random-start') is commonly used for emergency fertility preservation in cancer patients. A few retrospective studies have been published evaluating LS in women undergoing ovarian stimulation in the context of IVF, but there is a lack of robust data on the comparative efficacy of LS versus FS.Although 'random start' is commonly used in cancer survivors, few retrospective and uncontrolled studies have been published evaluating luteal phase stimulation in women undergoing ovarian stimulation in the context of IVF. Owing to this evident lack of robust data on the efficacy of LS, guidelines typically recommend the LS approach only for medical reasons and not in the context of IVF.

STUDY DESIGN, SIZE, DURATION

This is a prospective, equivalence study, with repeated stimulation cycles, conducted between May 2018 and December 2021. Overall, 44 oocyte donors underwent two identical consecutive ovarian stimulation cycles, one initiated in the FS and the other in the LS. The primary outcome of the study was to evaluate whether FS and LS in the same patient would result in equivalent numbers of euploid embryos following fertilization of oocytes with the same sperm sample.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall, 44 oocyte donors underwent two consecutive ovarian stimulation protocols with 150 μg corifollitropin alpha followed by 200 IU recombinant FSH (rFSH) in a fixed GnRH antagonist protocol. The only difference between the two cycles was the day of initiation of ovarian stimulation, which was in the early follicular phase (FS) in one cycle, and in the luteal phase (LS) in the other. Forty-four oocyte recipients participated in the study receiving a mean of six metaphase II (MII) oocytes from each stimulation cycle (FS and LS). All MIIs were inseminated with the corresponding recipient's partner sperm (which had been previously frozen) or donor sperm, in order to safeguard the use of the same sample for either the FS or LS. Following fertilization and blastocyst culture, all generated embryos underwent genetic analysis for aneuploidy screening (preimplantation genetic testing for aneuploidy).

MAIN RESULTS AND THE ROLE OF CHANCE

FS resulted in a significantly shorter duration of ovarian stimulation (difference between means (DBM) -1.05 (95% CI -1.89; -0.20)) and a lower total additional dose of daily rFSH was needed (DBM -196.02 (95% CI -319.92; -72.12)) compared with LS. The donors' hormonal profile on the day of trigger was comparable between the two stimulation cycles, as well as the mean number of oocytes (23.70 ± 10.79 versus 23.70 ± 8.81) (DBM 0.00 (95% CI -3.03; 3.03)) and MII oocytes (20.27 ± 9.60 versus 20.73 ± 8.65) (DBM -0.45 (95% CI -2.82; 1.91)) between FS and LS cycles, respectively. Following fertilization, the overall blastocyst formation rate was 60.70% with a euploid rate of 57.1%. Comparisons between the two stimulation cycles did not reveal any significance differences in terms of fertilization rates (71.9% versus 71.4%), blastocyst formation rates (59.4% versus 62%) and embryo euploidy rates (56.9 versus 57.3%) for the comparison of FS versus LS, respectively. The mean number of euploid blastocysts was equivalent between the FS (1.59 ± 1.30) and the LS (1.61 ± 1.17), (DBM -0.02 (90%CI -0.48; 0.44)).

LIMITATIONS, REASONS FOR CAUTION

The study was performed in young, potentially fertile oocyte donors who are patients with high blastocyst euploidy rates. Although results may be extrapolated to young infertile women with good ovarian reserve, caution is needed prior to generalizing the results to infertile women of older age.

WIDER IMPLICATIONS OF THE FINDINGS

The current study provides evidence that initiation of ovarian stimulation in the luteal phase in young potentially fertile women may result in a comparable number of oocytes and comparable blastocyst euploidy rates compared with follicular phase stimulation. This may imply that in case of a freeze-all protocol in young patients with good ovarian reserve, clinicians may safely consider initiation of ovarian stimulation during the luteal phase.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by an unrestricted grant from MSD/Organon. N.P.P. has received Research grants and honoraria for lectures from: Merck Serono, MSD/Organon, Ferring Pharmaceuticals, Besins Intenational, Roche Diagnostics, IBSA, Theramex, Gedeon Richter. F.M., E.C., M.R. and S.G. declared no conflict of interests.

TRIAL REGISTRATION NUMBER

The study was registered at Clinical Trials Gov (NCT03555942).

Monozygotic twin rate among ART centers: a multicenter analysis of data from 18 Italian units

PURPOSE

The risk of monozygotic twins (MZTs) is increased in couples undergoing assisted reproductive technology (ART) treatments. Several systematic reviews have investigated the possible determinants linked to ART, but results obtained have not been conclusive. The study aims to investigate whether the incidence of MZT differed among ART centers.

METHODS

This is a multicenter retrospective cohort study using the Italian ART National Registry database and involving the centers reporting data from individual ART cycles from 2015 to 2019. To investigate the incidence of MZT, only single embryo transfer cycles were considered. Women who had sex-discordant deliveries were excluded. MZT rate was calculated as the number of multiple pregnancies (more than one gestational sac at first ultrasound) out of the total number of clinical pregnancies. A binomial distribution model was used to determine the 95% CI of the frequency of MZT.

RESULTS

Eighteen centers were included, and they provided data on 10,433 pregnancies. The total number of MZT was 162, corresponding to an incidence of 1.5% (95% CI: 1.3-1.8%). The rate of MZT among centers varied between 0% (95% CI: 0.0-25.9%) and 3.2% (95% CI: 1.3-8.1%). All the 95% CIs included 1.5%, rejecting the hypothesis that the MZT rate may significantly differ among centers.

CONCLUSIONS

The rate of MZT did not significantly vary among ART centers. Local factors are unlikely to explain the increased rate of MZT in ART pregnancies.

Frequency of embryos appropriate for transfer following preimplantation genetic testing for monogenic disease

PURPOSE

To identify specific likelihoods that an embryo will be classified as appropriate for transfer after preimplantation genetic testing for detection of a monogenic disorder (PGT-M), with or without preimplantation genetic testing for aneuploidy (PGT-A), separated by inheritance pattern.

METHODS

Retrospective chart review of 181 selected PGT-M cycles performed at CooperGenomics in 2018 or 2019. For each cycle, the following main outcome data was collected: the number of embryos classified as affected with monogenic disease, the number detected to be chromosomally abnormal, the number that were recombinant, the number that had no result, and if applicable, the number which were aneuploid.

RESULTS

There were significantly fewer embryos appropriate to consider for transfer when PGT-A was included for autosomal recessive and X-linked disorders. There were also fewer for autosomal dominant disorders, though this was not statistically significant. When PGT-A was not included, 45.8% of autosomal dominant, 69% of autosomal recessive, and 47.8% of X-linked embryos were appropriate to consider for transfer. When PGT-A analysis was included, 29% of autosomal dominant, 41% of autosomal recessive, and 22% of X-linked embryos were appropriate to consider for transfer. 96.8% of women elect to include PGT-A when pursuing PGT-M.

CONCLUSION

This study resulted in specific likelihoods that an embryo would be found appropriate for clinicians and patients to consider for transfer based on the inheritance pattern of the monogenic disease being tested for and whether aneuploidy analysis was included.

The effect of ovarian stimulation on aneuploidy of early aborted tissues and preimplantation blastocysts: comparison of the GnRH agonist long protocol with the GnRH antagonist protocol

PURPOSE

To compare aneuploidy rates in early aborted tissues or blastocysts between in vitro fertilization (IVF) cycles after the gonadotropin-releasing hormone (GnRH) antagonist (GnRH-ant) protocol or the GnRH agonist (GnRH-a) long protocol.

METHODS

This was a retrospective cohort study from a university-affiliated fertility center. In total, 550 early miscarriage patients who conceived through IVF/intracytoplasmic sperm injection (ICSI) after receiving the GnRH-ant or GnRH-a long protocol were analyzed to compare aneuploidy rates in early aborted tissues. To compare aneuploidy rates in blastocysts, 404 preimplantation genetic testing for aneuploidy (PGT-A) cycles with the GnRH-ant protocol or GnRH-a long protocol were also analyzed.

RESULTS

For early miscarriage patients who conceived through IVF/ICSI, compared to the GnRH-a long protocol group, the GnRH-ant protocol group had a significantly higher rate of aneuploidy in early aborted tissues (48.51% vs. 64.19%). Regarding PGT-A cycles, the rate of blastocyst aneuploidy was significantly higher in the GnRH-ant protocol group than the GnRH-a long protocol group (39.69% vs. 52.27%). After stratification and multiple linear regression, the GnRH-ant regimen remained significantly associated with an increased risk of aneuploidy in early aborted tissues and blastocysts [OR (95% CI) 1.81 (1.21, 2.71), OR (95% CI) 1.65 (1.13, 2.42)]. Furthermore, the blastocyst aneuploidy rate in the GnRH-ant protocol group was significantly higher but only in young and normal ovarian responders [OR (95% CI) 5.07 (1.99, 12.92)].

CONCLUSION

Compared to the GnRH-a long protocol, the GnRH-ant protocol is associated with a higher aneuploidy rate in early aborted tissues and blastocysts. These results should be confirmed in a multicenter, randomized controlled trial.

PGT for structural chromosomal rearrangements in 300 couples reveals specific risk factors but an interchromosomal effect is unlikely

RESEARCH QUESTION

What factors affect the proportion of chromosomally balanced embryos in structural rearrangement carriers? Is there any evidence for an interchromosomal effect (ICE)?

DESIGN

Preimplantation genetic testing outcomes of 300 couples (198 reciprocal, 60 Robertsonian, 31 inversion and 11 complex structural rearrangement carriers) were assessed retrospectively. Blastocysts were analysed either by array-comparative genomic hybridization or next-generation sequencing techniques. ICE was investigated using a matched control group and sophisticated statistical measurement of effect size (φ).

RESULTS

300 couples underwent 443 cycles; 1835 embryos were analysed and 23.8% were diagnosed as both normal/balanced and euploid. The overall cumulative clinical pregnancy and live birth rates were 69.5% and 55.8%, respectively. Complex translocations and female age (≥35) were found to be risk factors associated with lower chance of having a transferable embryo (P < 0.001). Based on analysis of 5237 embryos, the cumulative de-novo aneuploidy rate was lower in carriers compared to controls (45.6% versus 53.4%, P < 0.001) but this was a 'negligible' association (φ < 0.1). A further assessment of 117,033 chromosomal pairs revealed a higher individual chromosome error rate in embryos of carriers compared to controls (5.3% versus 4.9%), which was also a 'negligible' association (φ < 0.1), despite a P-value of 0.007.

CONCLUSIONS

These findings suggest that rearrangement type, female age and sex of the carrier have significant impacts on the proportion of transferable embryos. Careful examination of structural rearrangement carriers and controls indicated little or no evidence for an ICE. This study helps to provide a statistical model for investigating ICE and an improved personalized reproductive genetics assessment for structural rearrangement carriers.

PGT-A: The biology and hidden failures of randomized control trials

OBJECTIVE

PGT-A for embryo selection has undergone significant advancements in the last two decades and yet many studies still fail to demonstrate any clinical benefits over traditional embryo morphology selection. To understand this conundrum, we performed a multi-center clinical study of PGT-A patients, where morphology selection (Mo-S) and euploid selection (Eu-S) outcomes were directly compared.

METHOD

All suitable blastocysts were biopsied and analysed for chromosome copy number. Outcomes (positive beta hCG, implantation, ongoing pregnancy and live birth rates) for euploid selection were compared to morphology selection using single embryo transfers RESULTS: Compared to Eu-S embryos, Mo-S embryos resulted in significant reduction of outcomes for positive beta hCG (P=0.0005), implantation (P=0.0008), ongoing pregnancy (P=0.0046), livebirth (P=0.0112), babies per transfer (P=0.0112) and babies per embryo transferred (P=0.0112). Morphology selection resulted in patients of all age groups having non-euploid embryos chosen for transfer. Post-hoc evaluation of individual clinic performances showed variable transfer outcomes that could potentially confound the true benefits of PGT-A.

CONCLUSION

Embryo chromosome status is central to improved embryo transfer outcomes and sole reliance on current morphology-based selection practices, without euploid selection, will always compromise outcomes. Often overlooked but a major effector of successful PGT-A outcomes are individual clinic performances. This article is protected by copyright. All rights reserved.

Dual Trigger with hCG Plus GnRHa for Final Oocyte Maturation in PGT-A Cycles Results in Similar Euploidy Rates when Compared to hCG-Only Trigger

Factors that may have an effect on euploidy rate of blastocysts have been investigated thoroughly in the literature. We aimed to assess whether dual trigger alters the ploidy chance of a blastocyst in preimplantation genetic screening for aneuploidy (PGT-A) cycles. This retrospective cohort study was conducted in a total of 385 PGT-A cycles at a single tertiary center for various indications. Final oocyte maturation was triggered using human chorionic gonadotropin (hCG) or the combination of hCG and gonadotropin-releasing hormone agonists (GnRHa) (dual trigger). Participants were divided based on triggering method and all demographic and clinical characteristics of the patients were compared. Final oocyte maturation was triggered in 143 cycles with hCG (37.1%), and in 242 cycles with dual trigger (62.9%). The duration of stimulation was shorter in the dual trigger arm compared to the hCG trigger group (10.0 ± 1.6 vs. 9.4 ± 1.4 days, p ≤ .001). Euploidy rates per blastocyst tested were 23.4% and 26.1% respectively for hCG and dual trigger groups without significance. Similar rates of euploidy were noted, even after age stratification. There was no significant difference between the groups regarding positive pregnancy result and ongoing pregnancy rates (p = .779 vs. p = .188). Although dual triggering, compared to hCG triggering, does not provide an additional superiority on blastocyst euploidy rate, further studies in women with different infertility etiology are needed to specifically evaluate the impact of triggering method on ploidy rates.

The effects of differences in trophectoderm biopsy techniques and the number of cells collected for biopsy on next‐generation sequencing results

Purpose

To examine how differences in trophectoderm biopsy techniques affect the frequency of mosaic embryos and sequencing results.

Methods

We examined differences in next‐generation sequencing (NGS) analysis results among operators or according to biopsy technique. Additionally, we determined the cut‐off for the number of collected cells to predict the occurrence of mosaicism. We collected cells according to the cut‐off value and examined whether there was a difference in the NGS analysis results between the pulling and flicking methods.

Results

There was no difference in the NGS analysis results among the operators. Regarding re‐biopsy, changes in the mosaic were observed in all specimens. The cut‐off value for the number of collected cells was five, and when more than five cells were collected, there was no difference in the NGS analysis results between the two methods.

Conclusions

We demonstrated that if trophectoderm biopsy techniques and NGS are stable, the cell collection location has a greater effect on NGS results than the biopsy technique.

On the origins and fate of chromosomal abnormalities in human preimplantation embryos: an unsolved riddle

About 8 out of 10 human embryos obtained in vitro harbour chromosomal abnormalities of either meiotic or mitotic origin. Abnormalities of mitotic origin lead to chromosomal mosaicism, a phenomenon which has sparked much debate lately as it confounds results obtained through preimplantation genetic testing for aneuploidy (PGT-A). PGT-A in itself is still highly debated, not only on the modalities of its execution, but also on whether it should be offered to patients at all.

We will focus on post-zygotic chromosomal abnormalities leading to mosaicism. First, we will summarize what is known of the rates of chromosomal abnormalities at different developmental stages. Next, based on the current understanding of the origin and cellular consequences of chromosomal abnormalities, which is largely based on studies on cancer cells and model organisms, we will offer a number of hypotheses on which mechanisms may be at work in early human development. Finally, and very briefly, we will touch upon the impact our current knowledge has on the practice of PGT-A. What is the level of abnormal cells that an embryo can tolerate before it loses its potential for full development? And is blastocyst biopsy as harmless as it seems?

Assessment of Telomere Length and Mitochondrial DNA Copy Number in Granulosa Cells as Predictors of Aneuploidy Rate in Young Patients

Background: To identify the correlation among female age, cellular aging markers, and aneuploidy rate in in vitro fertilization (IVF) and the preimplantation genetic test for aneuploidy (PGT-A) cycles. Methods: This is a prospective cohort study recruiting 110 infertile women between August 2017 and July 2018. They were divided into young-age (<38 years, n = 60) and advanced-age (≥38 years, n = 50) groups. Peripheral leukocytes were assessed, and the granulosa cells were pooled during oocyte pickup. Mitochondrial DNA (mtDNA) copy number and telomere length (TL) were measured using real-time polymerase chain reaction. PGT-A was performed on the NGS platform. Results: mtDNA copy number and TL were positively correlated in both leukocytes (rho = 0.477, p < 0.001) and granulosa cells (rho = 0.361, p < 0.001), but the two parameters in leukocytes were not correlated with those in granulosa cells. In the young-age group, TL in the granulosa cells was the only factor correlated with the aneuploidy rate (rho = −0.283, p = 0.044), whereas in the advanced-age group, age was the main factor (rho = 0.358, p = 0.018). Conclusions: TL in the granulosa cells was negatively correlated with the aneuploidy rate in the young-age group, supporting the application of PGT-A in younger women.

Controlled ovarian hyperstimulation parameters are not associated with de novo chromosomal abnormality rates and clinical pregnancy outcomes in preimplantation genetic testing

OBJECTIVE

This study aimed to determine whether controlled ovarian hyperstimulation (COH) parameters influence the incidence of de novo chromosomal abnormalities (> 4 Mb) in blastocysts and, thus, clinical pregnancy outcomes in preimplantation genetic testing (PGT).

METHODS

Couples who underwent preimplantation genetic testing for structural chromosome rearrangements (PGT-SR) and monogenic disorders (PGT-M) were included in this study. The relationships of maternal age, paternal age, stimulation protocol, exogenous gonadotropin dosage, duration of stimulation, number of oocytes retrieved and estradiol (E₂) levels on human chorionic gonadotropin (hCG) trigger day with the incidence of de novo chromosomal abnormalities were assessed. Blastocysts were biopsied, and nuclear DNA was sequenced using next-generation sequencing (NGS). Clinical pregnancy outcomes after single euploid blastocyst transfers under different COH parameters were assessed.

RESULTS

A total of 1,710 and 190 blastocysts were biopsied for PGT-SR and PGT-M, respectively. The rate of de novo chromosomal abnormalities was found to increase with maternal age (p< 0.001) and paternal age (p = 0.019) in the PGT-SR group. No significant differences in the incidence of de novo chromosomal abnormalities were seen for different maternal or paternal age groups between the PGT-SR and PGT-M groups (p > 0.05). Stratification analysis by gonadotropin dosage, stimulation protocol, duration of stimulation, number of retrieved oocytes and E₂ levels on hCG trigger day revealed that de novo chromosomal abnormalities and clinical pregnancy outcomes were not correlated with COH parameters after adjusting for various confounding factors.

CONCLUSION

The rate of de novo chromosomal abnormalities was found to increase with maternal or paternal age. COH parameters were found to not influence the incidence of de novo chromosomal abnormalities or clinical pregnancy outcomes.

Can Culture Media Impact Preimplantation Embryo Aneuploidy?

With continued improvements in blastocyst culture, cell sampling approaches, and genetic analysis platforms, the resulting improvements in embryo development and the resolution and accuracy of chromosome analysis have provided valuable insights into the preimplantation embryo. This includes the impact of in vitro culture conditions on chromosomal dynamics. Specifically, through analysis of embryo aneuploidy and mosaicism, a growing number of reports indicate that rates of chromosomal abnormalities can vary between IVF centers. Because differences in mosaicism reflect mitotic errors, this endpoint analysis suggests that IVF laboratory-controlled variables during embryo development may be influencing chromosome separation and segregation. A growing body of literature suggests that culture media may be one variable influencing preimplantation embryo aneuploidy and mosaicism. However, these data are far from definitive in demonstrating cause-and-effect. Whether reported differences may be due to media formulation, use of sequential media or single-step media, or uninterrupted culture approaches is unknown. Importantly, variables directly impacting media performance and embryo development, including pH, temperature, osmolality, and oxygen concentration, must also be considered and make it difficult to isolate the impact of culture media as the sole factor responsible. These IVF laboratory variables will be reviewed and literature suggesting a possible link to mitotic aneuploidy/mosaicism will be discussed.

Aneuploidy rates and morphokinetic parameters of embryos cultured in distinct culture media: a sibling oocyte study

STUDY QUESTION

Do embryos from sibling oocytes assigned to distinct single-step media culture systems demonstrate differences in early embryo development, morphokinectics or aneuploidy rates?

SUMMARY ANSWER

Embryo quality, morphokinetic parameters and aneuploidy rates from trophectoderm biopsy were similar between sibling embryos cultured in distinct media systems from the time of gamete isolation.

WHAT IS KNOWN ALREADY

Studies on the effect of commercially available embryo culture media systems have demonstrated inconsistent impact on human embryonic development, morphokinetics, aneuploidy rates and clinical outcomes. In addition, these studies have been primarily randomized at the level of the embryo or the patient to culture media.

STUDY DESIGN, SIZE, DURATION

Prospective sibling oocyte cohort derived from 200 subjects undergoing IVF at a tertiary academic medical center between February 2018 and November 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sibling oocytes were allocated to Global® or SAGE® media system based upon laterality of ovary from which they were retrieved. All embryos were cultured in a time-lapse incubator. Blastocysts underwent trophectoderm biopsy for preimplantation genetic testing for aneuploidy using next-generation sequencing.

MAIN RESULTS AND THE ROLE OF CHANCE

One hundred twenty-seven subjects (n = 127) had paired blastocysts for biopsy in each culture media system. There was no difference in top quality blastocyst formation (47.1 ± 31.0 vs 48.1 ± 27.2%; P = 0.87) nor aneuploidy rate (62.3 ± 34.0 vs 56.1 ± 34.4%; P = 0.07) for sibling embryos cultured in Global versus SAGE media system. Embryo morphokinetic parameters including time to each cell division from two cells (t2) to eight cells (t8), time to morula stage (tM), time to blastocele formation (tSB), time to fully formed blastocyst (tB) and time to expansion of the blastocyst (tEB) were similar between paired blastocysts from each culture media system.

LIMITATIONS, REASONS FOR CAUTION

Pregnancy outcomes and offspring health data were not available for analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Commercially available culture media may not have a differential impact on embryo development and blastocyst aneuploidy rate when patient and stimulation-related factors are held constant.

STUDY FUNDING/COMPETING INTEREST(S)

There was no external funding for this study. C.H. is owner of a consultancy company, IVF Professionals, Chief Scientific Officer at Apricity, Executive Director at TMRW and co-owner and shareholder of Aria Fertility. She has received speaker fees, consulting fees and travel support from Cooper Surgical and Vitrolife. J.B. is an employee and shareholder of vitrolife.

TRIAL REGISTRATION NUMBER

N/A.

Preimplantation genetic testing for aneuploidies does not increase success rates in fresh oocyte donation cycles: a paired cohort study

PURPOSE

To determine whether in vitro fertilization cycles using fresh oocyte donations benefit from preimplantation genetic testing for aneuploidies.

METHODS

A paired cohort study compared 44 fresh oocyte donation cycles with or without preimplantation genetic testing for aneuploidy (PGT-A). The sibling oocyte study analyzed fertilized oocytes, blastocyst development, and euploidy rate. Only frozen embryo transfers were performed. Pregnancy, implantation, biochemical pregnancy, miscarriage, stillbirth, live birth, and twin pregnancy rates were analyzed between groups.

RESULTS

Fresh oocyte donation cycles between PGT-A and non-PGT-A groups were similar in all laboratory and clinical outcomes. A euploidy rate of 74.2% was observed in the PGT-A group. Although a slight trend was observed for implantation rate in the PGT-A group, it was not statistically significant. No difference was observed for live birth between groups.

CONCLUSION

PGT-A associated with fresh oocyte donation cycles does not improve clinical outcomes and can be seen as over-treatment for patients.

IVF embryo choices and pregnancy outcomes

OBJECTIVE

Investigate the chromosome status and transfer outcomes of embryos selected using routine "best morphology" IVF practices.

METHOD

A prospective multi-center, non-selection cohort study involving patients undertaking IVF treatment. Study entry conditions were blastocyst biopsy, >1 embryo with chromosome analysis and frozen transfer of the best morphology embryo. Primary analyses were βhCG positive, implantation, ongoing pregnancy and birth rates and pregnancy-stage progression failures.

RESULTS

After transfer, embryo chromosome status was assigned and outcomes divided into two primary groups - euploids (n = 135) and aneuploids (n = 53). Compared to euploid embryo transfers, aneuploid embryos had significantly lower primary outcomes (+βhCG: 67% vs. 30%, p < 0.0001; IR: 56% vs. 19%, p < 0.0001; ongoing week 12: 51% vs. 9%, p < 0.0001; and livebirths: 50% vs. 8%, p < 0.0001, respectively). Transfers were further subdivided into smaller groups according to their main chromosomal feature. Stage analysis showed higher failure rates for aneuploids to initiate a pregnancy (p < 0.0001), higher subclinical miscarriage rate (p = 0.0402) and higher clinical miscarriage rate (p = 0.0038).

CONCLUSION

Routine morphology-based embryo selection resulted in a high euploid selection rate but a significant number of aneuploid embryos were still inadvertently selected for transfer (28%) with the subsequent high failure rates for pregnancy initiation and progression having implications for appropriate patient management.

Preimplantation genetic testing is not a preferred recommendation for patients with X chromosome abnormalities

STUDY QUESTION

Should women with X chromosome abnormalities (XCAs) be recommended to have embryos selected by both morphological and cytogenetic assessment through preimplantation genetic testing (PGT) rather than morphological assessment only in conventional IVF/ICSI treatment?

SUMMARY ANSWER

PGT is not a preferred recommendation for women with XCAs in the absence of other PGT indications.

WHAT IS KNOWN ALREADY

XCAs are the most frequent sort of chromosomal aberrations in infertile women. Patients with a complete or partial absence of one X chromosome, diagnosed as Turner Syndrome (TS), demonstrate low spontaneous pregnancy rates (5-7%) and high miscarriage rates (22.8-30.8%), as well as high chances of birth defects (20%). PGT is known to improve pregnancy rates and decrease the incidence of miscarriage in couples with chromosomal aberrations such as Robertsonian and reciprocal translocations and Klinefelter Syndrome.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study was conducted with 394 women with XCAs and undergoing their first oocyte retrieval and first embryo transfer cycle from June 2011 to August 2019 in the Reproductive Hospital Affiliated to Shandong University.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pregnancy outcomes were compared between the conventional IVF/ICSI group (n = 284) and the PGT group (n = 110) in the first fresh or frozen embryo transfer cycle for each woman with XCAs. Three platforms were applied in PGT: fluorescence in situ hybridisation (FISH, n = 34), array comparative genomic hybridisation (aCGH, n = 24) and next-generation sequencing (NGS, n = 51). The embryo aneuploidy rate and distribution of embryonic chromosomal aberrations revealed by aCGH or NGS were analysed and stratified by maternal age and type of XCAs to assess the effect of maternal XCAs on embryo karyotypes.

MAIN RESULT AND THE ROLE OF CHANCE

The live birth rate (LBR) per embryo transfer was similar between the PGT group and IVF/ICSI group both in the first cycle of fresh or frozen embryo transfer respectively (39.13% in PGTFISH vs 42.58% in IVF/ICSI, Padj=0.558; 66.67% in PGTFISH vs 52.08% in PGTaCGH/NGS vs 53.06% in IVF/ICSI, Padj=0.756), as was the clinical pregnancy rate (60.87% in PGTFISH vs 50.97% in IVF/ICSI, Padj =0.672; 88.89% in PGTFISH vs 58.33% in PGTaCGH/NGS vs 69.39% in IVF/ICSI, Padj =0.480) and the pregnancy loss rate (35.71% in PGTFISH vs 16.46% in IVF/ICSI, Padj =0.136; 12.50% in PGTFISH vs 10.71% in PGTaCGH/NGS vs 23.53% in IVF/ICSI, Padj =0.352). The rates of maternal and neonatal complications were also comparable between the PGT and IVF/ICSI groups with fresh and frozen transfers respectively (10.00% vs 8.85%, P = 1.000; 21.74% vs 14.55%, P = 0.272). Intriguingly, the distribution of embryonic chromosome abnormalities was more frequent on autosomes 22 (20.39%), 21 (18.45%) and 16 (17.47%), compared with the X chromosome (8.73%).

LIMITATIONS, REASONS FOR CAUTION

Selection bias is an inherent drawback of a retrospective study. First, our participants hosted 4.84% X chromosome mosaicism with few typical somatic anomalies of TS. Second, the incidences of history of recurrent miscarriage and abnormal offspring in the PGT group were higher than in IVF/ICSI group although binary logistic regression analysis was performed to attenuate the modifying effect of confounding factors. Third, FISH performed in this study only used X/Y probes and lacked the reference of autosome, which might have resulted in misdiagnosis and bias. Finally, intrinsic disadvantages could not be totally avoided due to the retrospective nature of this study.

WIDER IMPLICATION OF THE FINDINGS

In the current study, comparable pregnancy outcomes were revealed among a large cohort of women with XCAs undergoing their first cycles of PGT or conventional IVF/ICSI treatment. Moreover, the X chromosome abnormality was illustrated to cause no higher frequency of aberrations in embryos. Our data provided perspectives for genetic and reproductive counselling to XCAs individuals and their families.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by National Research and Development Plan (2016YFC1000604 and 2017YFC1001100), the National Natural Science Foundation of China (81701406), Shandong Science Fund for Distinguished Young Scholars (JQ201720), Taishan Scholars Program for Young Experts of Shandong Province (tsqn20161069) and Projects of Medical and Health Technology Development Program in Shandong Province (202005010520, 202005010523 and 2016WS0368). There is no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Embryos are exposed to a significant drop in temperature during the embryo transfer procedure: a pilot study

RESEARCH QUESTION

During the embryo transfer procedure, to what degree of temperature drop are embryos exposed to between loading the transfer catheter and placing it into the uterus?

DESIGN

Twenty-nine simulated embryo transfer procedures were carried out across five clinics. A thermocouple probe was used for standardized measurements inside the embryo transfer catheter to investigate the change in temperature that occurred in the time period between loading and placing the catheter in the uterus.

RESULTS

In all cases, the temperature at the loaded catheter tip fell rapidly to ambient temperature during transit from the embryo transfer workstation in the laboratory to the procedure room, even though embryo transfer procedures, ambient temperatures and embryo transfer catheter temperatures at loading varied between clinics.

CONCLUSIONS

Given the sensitivity of the pre-implantation embryo to its immediate environment, the rapid and profound drop in temperature observed at the catheter tip that houses the embryo during transit from laboratory to the uterus may affect embryo viability and health. This issue should be addressed to ensure that the tight temperature control aimed for by IVF laboratories continues throughout the embryo transfer procedure, and could improve clinical outcomes.

First PGT-A using human in vivo blastocysts recovered by uterine lavage: comparison with matched IVF embryo controls†

STUDY QUESTION

After controlled ovarian stimulation (COS) and IUI, is it clinically feasible to recover in vivo conceived and matured human blastocysts by uterine lavage from fertile women for preimplantation genetic testing for aneuploidy (PGT-A) and compare their PGT-A and Gardner scale morphology scores with paired blastocysts from IVF control cycles?

SUMMARY ANSWER

In a consecutive series of 134 COS cycles using gonadotrophin stimulation followed by IUI, uterine lavage recovered 136 embryos in 42% (56/134) of study cycles, with comparable in vivo and in vitro euploidy rates but better morphology in in vivo embryos.

WHAT IS KNOWN ALREADY

In vivo developed embryos studied in animal models possess different characteristics compared to in vitro developed embryos of similar species. Such comparative studies between in vivo and in vitro human embryos have not been reported owing to lack of a reliable method to recover human embryos.

STUDY DESIGN, SIZE, DURATION

We performed a single-site, prospective controlled trial in women (n = 81) to evaluate the safety, efficacy and feasibility of a novel uterine lavage catheter and fluid recovery device. All lavages were performed in a private facility with a specialized fertility unit, from August 2017 to June 2018. Subjects were followed for 30 days post-lavage to monitor for clinical outcomes and delayed complications. In 20 lavage subjects, a single IVF cycle (control group) with the same ovarian stimulation protocol was performed for a comparison of in vivo to in vitro blastocysts.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Women were stimulated with gonadotrophins for COS. The ovulation trigger was given when there were at least two dominant follicles ≥18 mm, followed by IUI of sperm. Uterine lavage occurred 4–6 days after the IUI. A subset of 20 women had a lavage cycle procedure followed by an IVF cycle (control IVF group). Recovered embryos were characterized morphologically, underwent trophectoderm (TE) biopsy, vitrified and stored in liquid nitrogen. Biopsies were analyzed using the next-generation sequencing technique. After lavage, GnRH antagonist injections were administered to induce menstruation.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 134 lavage cycles were performed in 81 women. Uterine lavage recovered 136 embryos in 56 (42%) cycles. At the time of cryopreservation, there were 40 (30%) multi-cell embryos and 96 (70%) blastocysts. Blastocysts were of good quality, with 74% (70/95) being Gardener grade 3BB or higher grade. Lavage blastocysts had significantly higher morphology scores than the control IVF embryos as determined by chi-square analysis (P < 0.05). This is the first study to recover in vivo derived human blastocysts following ovarian stimulation for embryo genetic characterization. Recovered blastocysts showed rates of chromosome euploidy similar to the rates found in the control IVF embryos. In 11 cycles (8.2%), detectable levels of hCG were present 13 days after IUI, which regressed spontaneously in two cases and declined after an endometrial curettage in two cases. Persistent hCG levels were resolved after methotrexate in three cases and four cases received both curettage and methotrexate.

LIMITATIONS, REASON FOR CAUTION

The first objective was to evaluate the feasibility of uterine lavage following ovarian stimulation to recover blastocysts for analysis, and that goal was achieved. However, the uterine lavage system was not completely optimized in our earlier experience to levels that were achieved late in the clinical study and will be expected in clinical service. The frequency of chromosome abnormalities of in vivo and IVF control embryos was similar, but this was a small-size study. However, compared to larger historical datasets of in vitro embryos, the in vivo genetic results are within the range of high-quality in vitro embryos.

WIDER IMPLICATIONS OF THE FINDINGS

Uterine lavage offers a nonsurgical, minimally invasive strategy for recovery of embryos from fertile women who do not want or need IVF and who desire PGT, fertility preservation of embryos or reciprocal IVF for lesbian couples. From a research and potential clinical perspective, this technique provides a novel platform for the use of in vivo conceived human embryos as the ultimate benchmark standard for future and current ART methods.

STUDY FUNDING/COMPETING INTEREST(S)

Previvo Genetics, Inc., is the sole sponsor for the Punta Mita, Mexico, clinical study. S.M. performs consulting for CooperGenomics. J.E.B. and S.A.C. are co-inventors on issued patents and patents owned by Previvo and ownshares of Previvo. S.N. is a co-author on a non-provisional patent application owned by Previvo and holds stock options in Previvo. S.T.N. and M.J.A. report consulting fees from Previvo. S.T.N., S.M., M.V.S., M.J.A., C.N. and J.E.B. are members of the Previvo Scientific Advisory Board (SAB) and hold stock options in Previvo. J.E.B and S. M are members of the Previvo Board of Directors. A.N. and K.C. are employees of Previvo Genetics. L.V.M, T.M.M, J.L.R and S. S have no conflicts to disclose.

TRIAL REGISTRATION NUMBER

Protocol Registration and Results System (PRS) Trial Registration Number and Name: Punta Mita Study TD-2104: Clinical Trials NCT03426007.

The Effect of Teratozoospermia on Sex Chromosomes in Human Embryos

Purpose

The aim of this study is to evaluate the effect of abnormal semen morphology on the frequency of sex chromosomal abnormalities in embryos obtained by ICSI, which represents the first to be studied in Egyptian population.

Methods

Forty-two couples suffering from male infertility due to teratozoospermia were divided into two groups: patients with severe and moderate teratozoospermia (group A and B, respectively). All involved couples were subjected to careful history taking and had a normal clinical examination and karyotype. Females were subjected to hormonal assays, pelvic ultrasound, hysterosalpingography and yielded normal results, while male partners were subjected to computerized semen analysis. Preimplantation genetic diagnosis was performed for all suitably developed embryos including embryo biopsy, fixation of biopsied cells and fluorescent in situ hybridization (FISH) analysis.

Results

Couples included in the two groups were found to be homogenous in terms of age of both partners and duration of infertility. Interpretation of FISH results was performed by evaluation of embryos’ chromosomal constitution as regards abnormalities in chromosomes X, Y and 18. Twenty-seven embryos (48.2%) were found chromosomally abnormal in group A, while only 14 embryos (25.0%) were found chromosomally abnormal in group B. Aneuploidies involved only sex chromosomes were tripled in group A embryos when compared to their frequency in group B embryos (26.8% and 8.3%, respectively) with statistically significant difference between the two groups (p=0.002). Monosomies were the most common type of aneuploidy and were significantly higher in group A (14.3%) when compared to group B (3.6%) (p=0.047). Embryos with mosaic abnormalities were more common in group A (12.5%) when compared to group B (3.6%), however not statistically significantly different (p= 0.162). A significant difference between the two studied groups as regards the total number of potentially viable chromosomal abnormalities detected and the potentially viable sex chromosomal aneuploidies detected (p<0.001 and p=0.002), respectively.

Conclusion

The cases with severe teratozoospermia undergoing ICSI treatment can display a higher rate of sex chromosome aneuploidies in their embryos (threefold) than cases with moderate teratozoospermia.

Cost-effectiveness of preimplantation genetic testing for aneuploidy for fresh donor oocyte cycles

OBJECTIVE

To determine whether in vitro fertilization (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) is cost effective to achieve a live birth compared with IVF alone in fresh donor oocyte cycles.

DESIGN

Theoretical cost-effectiveness study.

SETTING

Not applicable.

PATIENTS

None.

INTERVENTIONS

Comparison between the cost of IVF with PGT-A vs. IVF alone to achieve a live birth. The model analyzed a hypothetical single fresh oocyte donor IVF cycle with PGT-A vs. IVF alone and followed the progression of a single embryo through the different decision nodes. Cost estimates assigned to each clinical event were based on data obtained from the literature and institutional costs.

MAIN OUTCOME MEASURES

Cost per live birth.

RESULTS

In the base-case analysis, IVF with PGT-A was not cost effective in fresh donor oocyte cycles when compared with IVF alone to achieve a live birth. The cycles using PGT-A cost an additional $6,018.66. The incremental cost-effectiveness ratio was found to be $119,606.59 per additional live birth achieved with IVF with PGT-A. Monte Carlo simulations demonstrated that IVF with PGT-A was not cost effective in nearly all iterations.

CONCLUSIONS

PGT-A in fresh donor oocyte IVF cycles is not cost effective compared with IVF alone over a wide range of probabilities and costs.

Multiple cryopreservation-warming cycles, coupled with blastocyst biopsy, negatively affect IVF outcomes

RESEARCH QUESTION

Do multiple cryopreservation-warming cycles, coupled with blastocyst biopsy, negatively affect IVF outcomes?

DESIGN

Patients undergoing IVF with homologous single embryo transfer, and who underwent trophectoderm biopsy for preimplantation genetic testing for aneuploidy (PGT-A) between 2013 and 2017, were divided into three groups based on degree of embryonic micromanipulation: once-biopsied, once-cryopreserved (group BC, n = 2603), once-biopsied, twice-cryopreserved (group CBC, n = 95) and twice-biopsied, twice-cryopreserved (group BCBC, n = 15). The primary outcome was live birth; secondary outcomes included positive serum pregnancy test, clinical pregnancy and miscarriage.

RESULTS

Group CBC had a significantly lower chance of live birth (adjusted RR 0.57, 95% CI 0.41 to 0.79) and clinical pregnancy (adjusted RR 0.67, 95% CI 0.53 to 0.85) compared with group BC. Miscarriage rates were similar between groups BC and CBC (adjusted RR 1.3, 95% CI 0.64 to 2.7).

CONCLUSIONS

Multiple cryopreservation-warming cycles, coupled with blastocyst biopsy, negatively affect IVF outcomes. Although PGT-A is thought to improve reproductive outcomes on a per transfer basis, caution must be exercised in counselling patients on the possibility of diminishing returns owing to further embryonic micromanipulation after an embryo has been cryopreserved.

Missed connections: recombination and human aneuploidy

The physical exchange of DNA between homologs, crossing-over, is essential to orchestrate the unique, reductional first meiotic division (MI). In females, the events of meiotic recombination that serve to tether homologs and facilitate their disjunction at MI occur during fetal development, preceding the MI division by several decades in our species. Data from studies in humans and mice demonstrate that placement of recombination sites during fetal development influences the likelihood of an MI nondisjunction event that results in the production of an aneuploid egg. Here we briefly summarize what we know about the relationship between aneuploidy and meiotic recombination and important considerations for the future of human assisted reproduction.

Effect of ovarian stimulation on embryo aneuploidy and mosaicism rate

There is a high incidence of chromosome abnormalities in human embryos that leads to a failed IVF cycle. Different studies have shown that maternal age is the determining factor in the appearance of chromosomal alterations in the embryo. However, the possible influence of ovarian stimulation on oocyte and embryo aneuploidies and mosaicism is controversial. A retrospective study was carried out in which 835 embryos from 280 couples undergoing reproductive treatment using their oocytes were chromosomally analyzed. A binary logistic regression analysis was performed to evaluate the relationship between different parameters characterizing controlled ovarian stimulation (COS) and the rate of aneuploidy and embryonic mosaicism. The embryo aneuploidy rate showed no association with the use of oral contraceptives, type, total and daily doses of gonadotropins, stimulation protocol type, and drugs used for ovulation trigger (p > 0.05). In contrast, the duration of the ovarian stimulation treatment was correlated with the aneuploidy rate: patients requiring more days of stimulation presented a lower rate of aneuploid embryos (p = 0.015). None of the variables studied showed any association with the rate of embryo mosaicism. However, the duration of COS showed association with the appearance of aneuploidy, suggesting that faster recruitment could be deleterious for those reassuming meiosis, yielding more abnormal karyotype.Abbreviations: IVF: in vitro fertilization; COS: controlled ovarian stimulation; PGT-A: preimplantation genetic test for aneuploidy; hCG: human chorionic gonadotropin; GnRH: gonadotropin-releasing hormone; LH: luteinizing hormone; FSH: follicle-stimulating hormone; NGS: next-generation sequencing; a-CGH: comparative genomic hybridization; TUNEL: Terminal transferase dUTP Nick End Labeling; FISH: fluorescent in situ hybridization.

Is there an association between paternal age and aneuploidy? Evidence from young donor oocyte-derived embryos: a systematic review and individual patient data meta-analysis

BACKGROUND

Delayed parenthood, by both women and men, has become more common in developed countries. The adverse effect of advanced maternal age on embryo aneuploidy and reproductive outcomes is well known. However, whether there is an association between paternal age (PA) and embryonic chromosomal aberrations remains controversial. Oocyte donation (OD) is often utilized to minimize maternal age effects on oocyte and embryo aneuploidy, thus providing an optimal model to assess the effect of PA. Several studies have revealed a higher than expected rate of aneuploidy in embryos derived from young oocyte donors, which warrants examination as to whether this may be attributed to advanced PA (APA).

OBJECTIVE AND RATIONALE

The objective of this systematic review and individual patient data (IPD) meta-analysis is to evaluate existing evidence regarding an association between PA and chromosomal aberrations in an OD model.

SEARCH METHODS

This review was conducted according to PRISMA guidelines for systematic reviews and meta-analyses. Medline, Embase and Cochrane databases were searched from inception through March 2020 using the (MeSH) terms: chromosome aberrations, preimplantation genetic screening and IVF. Original research articles, reporting on the types and/or frequency of chromosomal aberrations in embryos derived from donor oocytes, including data regarding PA, were included. Studies reporting results of IVF cycles using only autologous oocytes were excluded. Quality appraisal of included studies was conducted independently by two reviewers using a modified Newcastle-Ottawa Assessment Scale. A one-stage IPD meta-analysis was performed to evaluate whether an association exists between PA and aneuploidy. Meta-analysis was performed using a generalized linear mixed model to account for clustering of embryos within patients and clustering of patients within studies.

OUTCOMES

The search identified 13 032 references, independently screened by 2 reviewers, yielding 6 studies encompassing a total of 2637 IVF-OD cycles (n = 20 024 embryos). Two 'low' quality studies using FISH to screen 12 chromosomes on Day 3 embryos (n = 649) reported higher total aneuploidy rates and specifically higher rates of trisomy 21, 18 and 13 in men ≥50 years. One 'moderate' and three 'high' quality studies, which used 24-chromosome screening, found no association between PA and aneuploidy in Day 5/6 embryos (n = 12 559). The IPD meta-analysis, which included three 'high' quality studies (n = 10 830 Day 5/6 embryos), found no significant effect of PA on the rate of aneuploidy (odds ratio (OR) 0.97 per decade of age, 95% CI 0.91-1.03), which was robust to sensitivity analyses. There was no association between PA and individual chromosome aneuploidy or segmental aberrations, including for chromosomes X and Y (OR 1.06 per decade of age, 95% CI 0.92-1.21). Monosomy was most frequent for chromosome 16 (217/10802, 2.01%, 95% CI 1.76-2.29%) and trisomy was also most frequent for chromosome 16 (194/10802, 1.80%, 95% CI 1.56-2.06%).

WIDER IMPLICATIONS

We conclude, based on the available evidence, that APA is not associated with higher rates of aneuploidy in embryos derived from OD. These results will help fertility practitioners when providing preconception counselling, particularly to older men who desire to have a child.

Preimplantation genetic testing for aneuploidy: A Canadian Fertility and Andrology Society Guideline

The objective of this guideline from the Canadian Fertility and Andrology Society is to synthesize the evidence on preimplantation genetic testing for aneuploidies (PGT-A) using trophectoderm biopsy and 24-chromosome analysis and to provide clinical recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. To date, randomized controlled trials have been limited to good-prognosis patients who were able to generate two or more blastocysts for biopsy. In this specific population the GRADE analysis of PGT-A shows an increase in the implantation rate and ongoing pregnancy or delivery rate per transfer. Clearly, it is difficult to generalize from this subgroup of patients to the infertility population at large. As a result, the application of PGT-A should be individualized, and patient factors such as age and ability to generate embryos will influence decision-making. Comprehensive patient counselling and informed consent are imperative before undertaking PGT-A. Potential benefits must be weighed against the costs and limitations of the technology, including the risk of embryo damage, false positives, false negatives and the detection of embryonic mosaicism. Future research is required, especially with regard to the use of PGT-A in poorer prognosis patients, and with respect to reporting outcomes per cycle start and cumulatively per retrieval.

Donor oocyte recipients do not benefit from preimplantation genetic testing for aneuploidy to improve pregnancy outcomes

STUDY QUESTION

Do donor oocyte recipients benefit from preimplantation genetic testing for aneuploidy (PGT-A)?

SUMMARY ANSWER

PGT-A did not improve the likelihood of live birth for recipients of vitrified donor oocytes, but it did avoid embryo transfer in cycles with no euploid embryos.

WHAT IS KNOWN ALREADY

Relative to slow freeze, oocyte vitrification has led to increased live birth from cryopreserved oocytes and has led to widespread use of this technology in donor egg IVF programs. However, oocyte cryopreservation has the potential to disrupt the meiotic spindle leading to abnormal segregation of chromosome during meiosis II and ultimately increased aneuploidy in resultant embryos. Therefore, PGT-A might have benefits in vitrified donor egg cycles. In contrast, embryos derived from young donor oocytes are expected to be predominantly euploid, and trophectoderm biopsy may have a negative effect relative to transfer without biopsy.

STUDY DESIGN, SIZE, DURATION

This is a paired cohort study analyzing donor oocyte-recipient cycles with or without PGT-A performed from 2012 to 2018 at 47 US IVF centers.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Vitrified donor oocyte cycles were analyzed for live birth as the main outcome measure. Outcomes from donors whose oocytes were used by at least two separate recipient couples, one couple using PGT-A (study group) and one using embryos without PGT-A (control group), were compared. Generalized estimating equation models controlled for confounders and nested for individual donors contributing to both PGT-A and non-PGT-A cohorts, enabling a single donor to serve as her own control.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 1291 initiated recipient cycles from 223 donors were analyzed, including 262 cycles with and 1029 without PGT-A. The median aneuploidy rate per recipient was 25%. Forty-three percent of PGT-A cycles had only euploid embryos, whereas only 12.7% of cycles had no euploid embryos. On average 1.09 embryos were transferred in the PGT-A group compared to 1.38 in the group without PGT-A (P < 0.01). Live birth occurred in 53.8% of cycles with PGT-A versus 55.8% without PGT-A (P = 0.44). Similar findings persisted in cumulative live birth from per recipient cycle.

LIMITATIONS, REASONS FOR CAUTION

Pooled clinical data from 47 IVF clinics introduced PGT-A heterogeneity as genetic testing were performed using different embryology laboratories, PGT-A companies and testing platforms.

WIDER IMPLICATIONS OF THE FINDINGS

PGT-A testing in donor oocyte-recipient cycles does not improve the chance for live birth nor decrease the risk for miscarriage in the first transfer cycle but does increase cost and time for the patient. Further studies are required to test if our findings can be applied to the young infertility patient population using autologous oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.