Does recurrent implantation failure exist? Prevalence and outcomes of five consecutive euploid blastocyst transfers in 123 987 patients

STUDY QUESTION

What are the clinical pregnancy and live birth rates in women who underwent up to two more euploid blastocyst transfers after three failures in the absence of another known factor that affects implantation?

SUMMARY ANSWER

The fourth and fifth euploid blastocyst transfers resulted in similar live birth rates of 40% and 53.3%, respectively, culminating in a cumulative live birth rate of 98.1% (95% CI = 96.5-99.6%) after five euploid blastocyst transfers.

WHAT IS KNOWN ALREADY

The first three euploid blastocysts have similar implantation and live birth rates and provide a cumulative live birth rate of 92.6%.

STUDY DESIGN, SIZE, DURATION

An international multi-center retrospective study was conducted at 25 individual clinics. The study period spanned between January 2012 and December 2022. A total of 123 987 patients with a total of 64 572 euploid blastocyst transfers were screened for inclusion.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients with a history of any embryo transfer at another clinic, history of any unscreened embryo transfer at participating clinics, parental karyotype abnormalities, the use of donor oocytes or a gestational carrier, untreated intracavitary uterine pathology (e.g. polyp, leiomyoma), congenital uterine anomalies, adenomyosis, communicating hydrosalpinx, endometrial thickness <6 mm prior to initiating of progesterone, use of testicular sperm due to non-obstructive azoospermia in the male partner, transfer of an embryo with a reported intermediate chromosome copy number (i.e. mosaic), preimplantation genetic testing cycles for monogenic disorders, or structural chromosome rearrangements were excluded. Ovarian stimulation protocols and embryology laboratory procedures including trophectoderm biopsy followed the usual practice of each center. The ploidy status of blastocysts was determined with comprehensive chromosome screening. Endometrial preparation protocols followed the usual practice of participating centers and included programmed cycles, natural or modified natural cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 105 (0.085% of the total population) patients met the criteria and underwent at least one additional euploid blastocyst transfer after failing to achieve a positive pregnancy test with three consecutive euploid blastocyst transfers. Outcomes of the fourth and fifth euploid blastocyst transfers were similar across participating centers. Overall, the live birth rate was similar with the fourth and fifth euploid blastocysts (40% vs 53.3%, relative risk = 1.33, 95% CI = 0.93-1.9, P value = 0.14). Sensitivity analyses excluding blastocysts biopsied on Day 7 postfertilization, women with a BMI >30 kg/m2, cycles using non-ejaculate or donor sperm, double-embryo transfer cycles, and cycles in which the day of embryo transfer was modified due to endometrial receptivity assay test result yielded similar results. Where data were available, the fourth euploid blastocyst had similar live birth rate with the first one (relative risk = 0.84, 95% CI = 0.58-1.21, P = 0.29). The cumulative live birth rate after five euploid blastocyst transfers was 98.1% (95% CI = 96.5-99.6%).

LIMITATIONS, REASONS FOR CAUTION

Retrospective design has its own inherent limitations. Patients continuing with a further euploid embryo transfer and patients dropping out from treatment after three failed euploid transfers can be systematically different, perhaps with regard to ovarian reserve or economic status.

WIDER IMPLICATION OF THE FINDINGS

Implantation failure seems to be mainly due to embryonic factors. Given the stable and high live birth rates up to five euploid blastocysts, unexplained recurrent implantation failure should have a prevalence of <2%. Proceeding with another embryo transfer can be the best next step once a known etiology for implantation failure is ruled out.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Sibling oocytes cultured in a time-lapse versus benchtop incubator: how time-lapse incubators improve blastocyst development and euploid rate

The aim was to study whether a limited exposure of embryos outside the incubator has an effect on embryo development, blastocyst quality and euploid outcomes. This retrospective study was performed at ART Fertility Clinics, Abu Dhabi, United Arab Emirates (UAE) between March 2018 and April 2020 and included 796 mature sibling oocytes that were split randomly between two incubators after intracytoplasmic sperm injection (ICSI): an EmbryoScope™ (ES) incubator and a benchtop incubator, G185 K-SYSTEMS (KS). The fertilization, cleavage, embryo/blastocyst qualities, useable blastocyst and euploid rates were assessed to evaluate the incubator performance. In total, 503 (63.2%) mature oocytes were cultured in the EmbryoScope and 293 (36.8%) in the K-SYSTEMS. No differences were observed in fertilization rate (79.3% vs 78.8%, P = 0.932), cleavage rate (98.5% vs 99.1%, P = 0.676) and embryo quality on Day 3 (P = 0.543) between both incubators, respectively. Embryos cultured in the EmbryoScope, had a significantly higher chance of being biopsied (64.8% vs 49.6%, P < 0.001). Moreover, a significantly higher blastocyst biopsy rate was observed on Day 5 in the EmbryoScope (67.8% vs 57.0%, P = 0.037), with a highly significant increased euploid rate (63.5% vs 37.4%, P = 0.001) and improved blastocyst quality (P = 0.008). We found that exposure of embryos outside the incubator may negatively affect the in vitro blastocyst development and euploid rate on Day 5.

Antimüllerian hormone (AMH) and age as predictors of preimplantation genetic testing for aneuploidies (PGT-A) cycle outcomes and blastocyst quality on day 5 in women undergoing in vitro fertilization (IVF)

PURPOSE

The objective of this study was to investigate whether women with diminished ovarian reserve who planned for PGT-A exhibit a lower number of blastocysts for biopsy, ploidy outcomes, and blastocyst quality on day 5, regardless of age.

METHODS

A retrospective analysis was performed between March 2017 and July 2020 at ART Fertility Clinics Abu Dhabi, including couples that were triggered for final oocyte maturation in an ovarian stimulated cycle planned for PGT-A. Patients were stratified into four AMH groups: < 0.65 ng/ml, 0.65-1.29 ng/ml, 1.3-6.25 ng/ml, and > 6.25 ng/ml; four age categories: ≤ 30, 31-35, 36-40, and > 40 years.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1410 couples with a mean maternal age of 35.2 ± 6.4 years and AMH of 2.7 ± 2.6 ng/ml were included. In a multivariate logistic regression analysis, controlling for age, the chance of having at least one blastocyst biopsied/stimulated cycle (1156/1410), the chance of having at least one euploid blastocyst/stimulated cycle (880/1410), and the chance of having one euploid blastocyst once biopsy was performed (880/1156) were affected in all patients with AMH < 0.65 ng/ml [AdjOR 0.18[0.11-0.31] p = 0.008)], [AdjOR 0.18 [0.11-0.29] p < 0.001], and [AdjOR 0.34 [0.19-0.61] p = 0.015] as well as in patients with AMH 0.65-1.29 ng/ml (AdjOR 0.52 [0.32-0.84] p < 0.001), (AdjOR 0.49 [0.33-0.72] p < 0.001), and (AdjOR 0.57 [0.36-0.90] p < 0.001), respectively. In a multivariate linear regression analysis, AMH values did not affect blastocyst quality (- 0.72 [- 1.03 to - 0.41] p < 0.001).

CONCLUSION

Irrespective of age, patients with diminished ovarian reserve (AMH < 1.3 ng/ml) have a lower chance of having at least one blastocyst biopsied and lower chance of having at least one euploid blastocyst per ovarian stimulated cycle. Blastocyst quality was not affected by AMH values.

P-201 Identifying patients benefiting from delayed-matured oocytes insemination

Study question

Are there any predictive factors supporting the decision of inseminating delayed-matured oocytes?

Summary answer

Patients with ≤59% mature oocytes at retrieval and/or Anti-Mullerian-Hormone (AMH) &gt;2.52 ng/ml have increased chances of obtaining a euploid embryo from delayed-matured oocytes.

What is known already

Approximately 15% of oocytes retrieved after ovarian stimulation are immature, at metaphase I (MI) or germinal-vesicle (GV) stages at the time of oocyte denudation. Performing IVM in those oocytes could permit an increase on the number of usable embryos. Nevertheless, the utility of delayed-matured oocytes varies greatly among IVF laboratories with relatively low success rates, hence its practice in daily routine might be counter-productive. Determining which patient population could benefit from such strategy is valuable thereof to the clinical practice. Moreover, data comparing euploid rates of embryos derived from delayed-matured oocytes with its mature sibling oocytes are needed.

Study design, size, duration

This observational study was performed at ART Fertility Clinics, Abu Dhabi, UAE, between January 2019 and June 2021. A total of 5454 cumulus oocytes complexes (COC) were retrieved from 469 ovarian stimulation cycles. Out of the retrieved COCs, 3473 oocytes were immediate at metaphase II (MII-D0), and 915 were delayed-metaphase II oocytes (MII-D1).

Participants/materials, setting, methods

Patients with primary and secondary infertility undergoing Controlled ovarian stimulation (COS) in standardized protocols for IVF/ICSI treatment were included. Ovum pick up performed 34-36h post final oocyte maturation trigger shot (TS). Insemination was done 39-41h post TS for the MII-D0, while MII-D1 ICSI was performed 63-68h post TS. All cycles were planned for Preimplantation Genetic Testing for Aneuploidies (PGT-A) at blastocyst stage using Next Generation Sequencing (NGS).

Main results and the role of chance

Fertilization rates significantly differed between MII-D0 and MII-D1 oocytes (69.54% vs 55.96%, p &lt; 0.001, respectively). Blastocyst utilization rates were significantly higher in MII-D0 group compared to MII-D1 group (59.47% vs 18.52%, p &lt; 0.001). However, no difference was observed in the rate of euploid blastocysts between MII-D0 and MII-D1 (46.3% vs 39.0%, p = 0.163).

As identified by univariant logistic regression analysis, the following parameters augmented the chances of obtaining at least 1 blastocyst for biopsy when MII-D1 were injected: AMH (OR 1.15, p &lt; 0.001), number of COCs collected (OR: 1.03, P = 0.005), maturation rate on day0 (OR: 0.19, P = 0.001).

When the multivariant analysis model was applied, AMH and maturation rate on day0 remained significant factors predicting the success of inseminating delayed-matured oocytes (OR:1.15, [CI:1.00-1.32], p = 0.045); OR:0.06, [CI:0.03-0.31], p &lt; 0.001, respectively), with cut off values of AMH &gt;2.52 ng/ml and maturity rate of ≤ 59%, being identified by ROC analysis.

Limitations, reasons for caution

ICSI of MII-D1 was performed with the fresh or frozen sperm samples from the previous day. Exact timing of polar body extrusion of delayed-matured MI/GV was not identified.

Wider implications of the findings

The results of this study might provide guidance to the IVF laboratories for targeting the patient population who would benefit from MII-D1 ICSI without adhering to unnecessary costs and workload.

Trial registration number

not applicable

P-137 ICM and TE quality significantly impact the live birth in euploid frozen blastocyst transfer cycles

Study question

Is the live birth rate (LBR) in euploid frozen blastocyst transfer (FET) affected by the quality of ICM (Inner cell mass) and TE (Trophectoderm)?

Summary answer

ICM and TE significantly impacts the LBR with a decline of LB from 57.3% (ICM-A) to 48.5% (ICM-B) to 22.1% (ICM-C) (p &lt; 0.001)

What is known already

The morphological blastocyst grading system proposed by Gardner-Schoolcraft remains the most accepted system to identify blastocysts with higher implantation potential. It relies on morphological features within the blastocyst, including ICM and TE. Several studies tried to identify the individual contribution of each. However, the conclusions remain contradictory and no clear consensus has yet been achieved. Due to heterogeneity of parameters evaluated between different publications, where embryos with unknown ploidy status were transferred in conjunction with a variability of stimulation protocols and in the number of transferred embryos, the real effect of the ICM and TE is difficult to infer.

Study design, size, duration

This two-center retrospective observational study includes a total of 977 euploid single FET cycles between March 2017 and March 2020 at ART Fertility Clinics Muscat, Oman and Abu Dhabi, UAE.

Participants/materials, setting, methods

Trophectoderm biopsies were analyzed with Next Generation Sequencing (NGS). All blastocysts available on D5 or D6 with a quality ≥ BL3CC were subjected to TE biopsy for PGT-A analysis and LBR was recorded. Vitrification/warming of blastocysts was performed using Cryotop method (Kitazato). Bivariate and multivariate analysis were performed between LB outcomes and ICM and TE grade while controlling for confounding factors.

Main results and the role of chance

A total of 977 single FET cycles were analyzed: 651 in hormone replacement therapy (HRT) and 326 in natural cycle regimen (NC) resulting in a 46.88% LBR. The mean patients’ age was 33.80 years with a mean Body Mass Index (BMI) of 26.80 kg/m2. Though all qualities of ICM and TE were associated with LB, blastocyst ICM-A LBR was statistically significantly higher (57.3%) than ICM-B (48.4%) and ICM-C (22.1%) (p &lt; 0.001). Similarly, blastocyst TE-A LBR was statistically significantly higher (59.2%) than TE- B (48.6%) and TE- C (30.3%) (p &lt; 0.001). Miscarriage rate was similar in all groups.

The grade of ICM and TE were significantly associated with Anti-Mullerian-Hormone (AMH) and day of blastocyst biopsy. Mean AMH (ng/ml) was higher in ICM groups (A: 3.78, B: 3.24, p &lt; 0.001) and TE group (A: 3.63, B: 3.38, p &lt; 0.05) compared to lower grade (ICM-C: 2.86, TE-C: 2.82).

In multivariate analysis, endometrial preparation for FET, BMI and AMH were the parameters influencing LBR: OR:1.45, [CI:1.07-1.96], p &lt; 0.015) for NC; OR 0.96 [CI:0.93-0.99], p = 0.004 for BMI; OR 0.95 [CI:0.90-1.00], p = 0.033 for AMH; Both, ICM-C and TE-C, resulted in a significantly lower chance of LB [ICM: OR 0.32, CI:0.17-0.61, p &lt; 0.001; TE: OR 0.44, CI:0.27-0.73, p = 0.002), compared to grade A.

Limitations, reasons for caution

The retrospective nature of the study and inter-observer variability in blastocyst scoring is a limitation. The physician/embryologist performing the embryo transfer could not been standardized due to the multicenter design. Randomized controlled studies are needed to determine whether ICM or TE should be prioritized in the selection of the blastocyst.

Wider implications of the findings

The ICM and TE scoring in FET may influence the LBR and should be considered as an important factor for the success of embryo transfer cycles. Whether these results can be extrapolated to fresh embryo transfer and to blastocysts with unknown ploidy status, needs further investigation.

Trial registration number

not applicable

Calcifediol (25OHD) Deficiency and Its Treatment in Women's Health and Fertility

Currently, there is abundant scientific evidence showing that the vitamin D endocrine system (VDES) is a highly complex endocrine system with multiple actions in different regions of the body. The unequivocal presence of vitamin D receptors in different tissues related to fertility, and to specific aspects of women’s health such as pregnancy, undoubtedly implies functions of this steroid hormone in both male and female fertility and establishes relationships with different outcomes of human gestation. In order to review the role of the VDES in human fertility, we evaluated the relationships established between 25-hydroxyvitamin D (calcifediol) deficiency and in vitro fertilization, as well as aspects related to ovarian reserve and fertility, and commonly diagnosed endocrinopathies such as polycystic ovary disease. Likewise, we briefly reviewed the relationships between calcifediol deficiency and uterine fibroids, as well as the role that treatment may have in improving human fertility. Finally, the best scientific evidence available on the consequences of calcifediol deficiency during pregnancy is reviewed in relation to those aspects that have accumulated the most scientific literature to date, such as the relationship with the weight of the newborn at the time of delivery, the appearance of preeclampsia, and the risk of developing gestational diabetes and its final consequences for the pregnancy. To date, there is no definitive consensus on the necessary dose for treatment of calcifediol deficiency in the therapeutic management of infertility or during pregnancy. Large prospective clinical intervention studies are needed to clarify the benefits associated with this supplementation and the optimal dose to use in each situation. Although most intervention studies to date have been conducted with cholecalciferol, due to its much longer history of use in daily care, the use of calcifediol to alleviate 25-hydroxyvitamin D deficiency seems safe, even during pregnancy. The unequivocal presence of vitamin D receptors in very different tissues related to human fertility, both male and female, as well as in structures typical of pregnancy, allows us to investigate the crucial role that this steroid hormone has in specific aspects of women’s health, such as pregnancy and the ability to conceive. Well-designed clinical studies are needed to elucidate the necessary dose and the best form of treatment to resolve the very common calcifediol deficiency in women of reproductive age.

Day 5 vs day 6 single euploid blastocyst frozen embryo transfers: which variables do have an impact on the clinical pregnancy rates?

OBJECTIVE

To determine which variables affect most the clinical pregnancy rate with positive fetal heartbeat (CPR FHB+) when frozen embryo transfer (FET) cycles are performed with day 5 (D5) or day 6 (D6) euploid blastocysts. Design and method A single center retrospective study was performed from March 2017 till February 2021 including all single FET cycles with euploid D5 or D6 blastocysts and transferred in natural cycles (NC) or hormone replacement therapy (HRT) cycles. Trophectoderm (TE) and inner cell mass (ICM) qualities were recorded before biopsy.

RESULTS

A total of 1102 FET cycles were included, 678 with D5 and 424 with D6 blastocysts. Pregnancy rate (PR), clinical PR (CPR), and CPR FHB+ were significantly higher with D5 blastocysts (PR: 70.7% vs 62.0%, OR = 0.68 [0.53-0.89], p = 0.004; CPR: 63.7% vs 54.2%, OR = 0.68 [0.52-0.96], p = 0.002 and CPR FHB+: 57.8% vs 49.8%, OR = 0.72 [0.53-0.96], p = 0.011). However, miscarriage rate (12.5% vs 11.4%, OR = 0.78 [0.48-1.26], p = 0.311) did not differ. From a multivariate logistic regression model, endometrial thickness (OR = 1.11 [1.01-1.22], p = 0.028), patient's age (OR = 1.03 [1.00-1.05], p = 0.021), BMI (OR = 0.97 [0.94-0.99], p = 0.023), and ICM grade C (OR = 0.23 [0.13-0.43], p < 0.001) were significant in predicting CPR FHB+.

CONCLUSION

Although clinical outcomes are higher with D5 blastocysts, CPR FHB+ is more affected by endometrial thickness, patient age, BMI, and ICM grade C rather than biopsy day or endometrial preparation protocol.

The position of the euploid blastocyst in the uterine cavity influences implantation

RESEARCH QUESTION

Does the position of the euploid blastocyst in the uterine cavity upon transfer, measured as distance in millimetres (mm) from the fundus (DFF) to the air bubble, influence implantation potential?

DESIGN

A total of 507 single/double euploid frozen embryo transfer (FET) cycles at blastocyst stage were included retrospectively between March 2017 and November 2018 at a single centre. The patients were on average 33.3 years old. The FET were performed in natural cycles (n = 151) or hormone replacement therapy cycles (n = 356).

RESULTS

Of the 507 transfers, 370 (73.0%) resulted in a pregnancy, defined as human chorionic gonadotrophin concentration over 15 mIU/ml, and 341 (67.3%) in a clinical pregnancy, with an implantation rate of 62.0% and ongoing pregnancy rate of 59.6% (302/507). When comparing the number of embryos transferred, the pregnancy rate, clinical pregnancy rate and ongoing pregnancy rate were significantly higher after double-embryo transfer (DET) (P = 0.002: P < 0.001 and P = 0.002). The quality of the blastocyst in the single-embryo transfer group had a positive effect on the pregnancy rate (A versus B, P = 0.016; A versus C, P = 0.003) and clinical pregnancy rate (A versus C, P = 0.013). After performing a multivariate logistic regression analysis to consider the effect of all explanatory variables, a negative effect between DFF and pregnancy (P = 0.001), clinical pregnancy (P = 0.001) and ongoing pregnancy (P = 0.030) was found. When all variables remained constant, an increase of 1 mm of DFF changed the odds of pregnancy by 0.882, of clinical pregnancy by 0.891 and of ongoing pregnancy by 0.925. No significant effect of DFF was found on the miscarriage outcome (P = 0.089).

CONCLUSIONS

The depth of blastocyst replacement inside the uterine cavity may influence the pregnancy, clinical pregnancy and ongoing pregnancy rates and should be considered as an important factor to improve the success of IVF cycles.

P–584 Female parental consanguinity is associated with a reduced ovarian reserve: a large observational study including 2198 women from the Arabian Peninsula

Study question

Is parental consanguinity associated with reduced ovarian reserve in women from the Arabian Peninsula? Summary answer: Women descending from consanguineous unions have a reduced ovarian reserve compared with daughters of non-consanguine couples.

What is known already

Consanguineous marriage is defined as marriage between second-degree cousins or closer, with high prevalence in the Arabian Peninsula societies. An increased incidence of autosomal recessive diseases has been described in consanguineous marriages compared with non-consanguineous marriages. Despite the known adverse genetic impact of consanguinity, most available studies focus on the fertility of the consanguine couple. Only few publications, including low number of women, evaluated the impact of consanguinity on the fertility of their offspring, suggesting that daughters of consanguine parents might have reduced fertility associated to reduced ovarian reserve.

Study design, size, duration

A retrospective large-scale observational study was performed including 2482 women from the Arabian Peninsula who had their serum AMH and AFC measured as part of their fertility assessment at ART Fertility Clinics (UAE and Oman), from May 2015 to November 2019.

Participants/materials, setting, methods

2482 women from the Arabian Peninsula, aged 19–50 years, were assessed. Consanguinity was defined as women whose parents were first-degree or second-degree cousins. Ovarian reserve was evaluated by Antral Follicle Count (AFC) with transvaginal ultrasound and serum AMH, measured by Elecsys (Cobas, Roche®) for all participants. Women with adnexal surgery history or/and hormonal treatment within previous three months (n = 284) were excluded. Ethical approval was obtained from the Research Ethics Committee (REFA040).

Main results and the role of chance

After excluding women with previous adnexal surgeries, 2198 women were included for analysis. A total of 605 participants (27.53%) were descendants from consanguineous unions and 1593 (72.47%) reported non-consanguineous kinship of their parents. AMH and AFC (mean±SD) for the consanguineous group were 2.62±2.88 ng/mL and 12.78±9.73 antral follicles, respectively; and AMH and AFC (mean±SD) for the non-consanguineous group were 2.65±2.91 ng/mL and 13.07±9.39 antral follicles, respectively. Women from the consanguinity group were significantly younger (mean±SD: 33.74±6.64 years old) compared with the non-consanguinity group (mean±SD: 34.78±6.64 years old, p &lt; 0.0001). Both groups were similar in BMI (mean±SD: 28.63±5.46 versus 28.41±5.60 kg/m2, p=ns), years of infertility (mean±SD: 3.80±3.68 vs 4.04±3.79, p=ns), type of infertility (primary/secondary), dress code (Hijab/Niqab) and smoking status. As expected, AMH and AFC exhibit an age-dependent decline. To evaluate the differences on ovarian reserve between both groups, a multivariate analysis was performed including age, consanguinity and AMH/AFC. Women from the consanguine group showed significantly lower levels of serum AMH (R2=0.264, p = 0.036) and AFC (R2=0.286, p = 0.003) compared with non-consanguineous women, and the highest differences were found for women below 35 years of age (AMH p = 0.035; AFC p = 0.001).

Limitations, reasons for caution

Despite the large number of women included, the retrospective study design is a limitation. Results have to be treated with caution before translating into other populations, as these data are obtained from women native to the Arabian Peninsula, with high sociocultural/religious/ethnical similarities, which might differ to other consanguine populations.

Wider implications of the findings: Female parental consanguinity is associated with reduced ovarian reserve in the studied population, that might contribute to infertility. Future studies should examine the genetic and epigenetic basis of the current findings. Comprehensive clinical evaluation should include extensive family history and subsequent counselling of the affected couples.

Trial registration number

Not applicable

P–677 Endometrial thickness, endometrial preparation protocol and number of euploid embryos transferred, significantly impact the live birth in frozen embryo transfer cycles

Study question

Is the live birth rate (LBR) in euploid frozen embryo transfer (FET) cycles affected by the endometrial thickness (EMT)?

Summary answer

A significantly higher LBR was observed in patients with an endometrial thickness of at least 7.5mm (46.24% vs. 54.63%)

What is known already

Parameters assessing the endometrium prior planning a FET include endometrial thickness, pattern and blood flow. The impact of the endometrial thickness on ART outcomes is controversial, with conflicting results published. A recent meta-analysis evaluated whether EMT could predict pregnancy outcomes and suggested that lower EMT was associated with lower incidence of clinical pregnancy rate (CPR), implantation rate (IR) and LBR. Due to heterogeneity of parameters evaluated between different publications, where embryos with unknown ploidy status were transferred, in conjunction with variability of stimulation protocols and the number of embryos transferred, the real effect of the EMT was difficult to infer.

Study design, size, duration

This was a two-center retrospective observational study including a total of 1522 euploid FET cycles between March 2017 and March 2020 at ART Fertility Clinics Muscat, Oman and Abu Dhabi, UAE.

Participants/materials, setting, methods

Trophectoderm biopsies were analyzed with Next Generation Sequencing (NGS). Vitrification/warming of blastocysts was performed using Cryotop method (Kitazato). EMT was measured by vaginal ultrasound prior initiating the progesterone administration (± 1 day) and LBR was recorded. Multivariate analysis was performed between LB outcomes and median EMT while controlling for confounding factors.

Main results and the role of chance

A total of 1522 FET cycles were analyzed: 975 single embryo transfer (SET) and 547 double embryo transfer (DET). The mean age of the patients was 33.38 years with a mean BMI of 27.1 kg/m2. FET were performed in EMT ranging from 3 to 15 mm and 50.52% resulted in a live birth. Though potentially all ranges of EMT were associated with LB, the median EMT in patients with LB was significantly higher than the median EMT of patients without LB (7.6mm vs. 7.4mm; p &lt; 0.001).

The dataset was stratified into two groups based on the median EMT (7.5mm): &lt; 7.5mm (n = 744 cycles) and ≥ 7.5mm (n = 778 cycles). A significantly higher live birth rate was observed in ≥ 7.5mm group (46.24% vs. 54.63%. p = 0.0012).

In multivariate analysis, EMT, FET endometrial preparation protocol, and number of embryos transferred were the main parameters influencing the chance to achieve LB: OR 1.10 [1.01–1.19], p &lt; 0.015 for the EMT; OR 1.84 [1.47–2.30], p &lt; 0.0001 for Natural Cycle protocol and OR 1.55 [1.25–1.93], p &lt; 0.0001 for DET. Intercept 0.18 [0.07–0.44] p &lt; 0.0002. Female age did not reach significance: OR 1.02 [1.00–1.04], p = 0.056.

Limitations, reasons for caution

Besides the retrospective nature of the study, the inter-observer variability in EMT assessment between different physicians is a limitation. The physician and embryologist performing the embryo transfer could not been standardized due to the multicenter design of the study.

Wider implications of the findings: The EMT in FET may influence the LBR and should be considered as an important factor for the success of embryo transfer cycles. Whether these results can be extrapolated to fresh embryo transfer and to blastocysts with unknown ploidy status, needs further investigation.

Trial registration number

Not applicable

P–698 Antimüllerian Hormone (AMH) value as a predictive marker of cycle ploidy outcome

Study question

Do woman with diminished ovarian reserve exhibit poor blastocyst formation and ploidy outcomes, irrespective of age?

Summary answer

Patients with extreme diminished ovarian reserve (AMH≤0.65ng/ml) have a lower chance to have at least one euploid blastocyst compared to their age-related reference population (AMH=1.3–6.25ng/ml).

What is known already

AMH is an established marker of the ovarian reserve for predicting ovarian response to ovarian stimulation and it is strongly correlated with female age.

However, it has been suggested that AMH is not only a quantitative, but also a qualitative biomarker of oocyte/embryo competence. Previous studies show conflicting outcomes as to whether reduced ovarian reserve per se is associated with decreased oocyte developmental competence, leading to increased aneuploidy rates in embryos independent of the patient’s age.

Study design, size, duration

A retrospective analysis was performed between March 2017 and July 2020 at ART Fertility Clinics (Abu Dhabi) including all couples that were triggered for final oocyte maturation and planned for Preimplantation Genetic Testing for Aneuploidies (PGT-A). Patients were stratified into four age categories [≤30, 31–35, 36–40, &gt;40 years]. For each age category patients were further divided into three AMH groups: ≤0.65ng/ml, 0.65–1.3ng/ml and 1.31–6.25ng/ml (reference group).

Participants/materials, setting, methods

Trophectoderm biopsy samples were subjected to Next Generation Sequencing. AMH serum levels (ng/ml) were determined using the commercial fully automated Elecsys® (Roche) assay. Patients with a Progesterone rise of &gt; 1.5ng/ml on the day of final oocyte maturation and patients with AMH values &gt;6.25ng/ml were excluded from the analysis. Per patient that was triggered, the chance to have at least one euploid blastocyst in that cycle, was calculated.

Main results and the role of chance

A total of 1.300 couples were included with an mean maternal age of 35.6±6.2 years, AMH of 2.1 ±1.5ng/ml and body mass index of 27.5±5.0 kg/m2. The chance to have at least one blastocyst biopsied per cycle was affected in all patients with extreme low AMH (≤0.65ng/ml), irrespective of age; ≤30 years: 58.33%–100.00%–94.84% (p &lt; 0.001); 31–35 years: 50.00%–74.55%–95.32% (p &lt; 0.001); 36–40 years: 56.52%–81.93%–92.56% (p &lt; 0.001) and ≥40 years: 38.06%–73.02%–88.24% (p &lt; 0.001), for AMH ≤0.65ng/ml, 0.65–1.3ng/ml and 1.31–6.25ng/ml, respectively. In all age categories, patients with AMH values ≤0.65ng/ml had a significantly reduced probability of having a euploid blastocyst compared to the reference group (1.31–6.25ng/ml). For women ≤30 years the chances of getting a euploid blastocyst decreased from 88.89% (n = 252) to 41.67% (n = 12) (OR 0.01 [0.03–0.30], p &lt; 0.001), for 31–35 years from 88.09% (n = 235) to 43.75% (n = 32) (OR 0.10 [0.05–0.23], p &lt; 0.001), for 36–40 years from 77.67% (n = 215) to 21.74% (n = 69) (OR 0.08 [0.04–0.15], p &lt; 0.001) and among women &gt;40 years from 29.42% (n = 102) to 6.45% (n = 155) (OR 0.16 [0.08–0–36], p &lt; 0.001). Woman within AMH range of 0.65–1.3ng/ml presented the same decreased probability of having a euploid blastocyst only when 31–35 (52.73%, n = 55) or 36–40 years old (56.63%, n = 83) (OR 0.15 [0.08–0.29], p &lt; 0.001 and OR 0.37 [0.22–0.64], p &lt; 0.001, respectively).

Limitations, reasons for caution

The main limitation of this study is its retrospective design.

Wider implications of the findings: AMH is a clear biomarker of oocyte-embryo competence. Incorporation of AMH-specific counseling recommendations into clinical practice guidelines, could lead to a more informed guidance on cycle ploidy outcomes, rather than age alone.

Trial registration number

Not applicable

P–360 Blastocyst biopsy day does have an impact on clinical pregnancies in different frozen embryo transfer (FET) regimens: natural cycle (NC) versus hormone replacement therapy (HRT)

Study question

Do euploid blastocysts biopsied on day (D) 5 or D6 differ in clinical pregnancy rates when single FET are performed in NC or HRT cycles?

Summary answer

In single FET cycles, euploid D5 blastocysts have higher clinical pregnancy rates than D6 in NC, while outcomes are comparable in HRT cycles. What is known already: The synchronization between the endometrium and the embryo development is fundamental for a successful implantation. When performing FET with euploid blastocysts biopsied on D5 or D6, higher clinical pregnancy rates have been reported with D5 blastocysts, however contradictory findings were described due to the study design heterogeneity and endometrial preparation (EP) protocol variabilities. In FET cycles, no consensus has been defined of the superiority of NC over HRT cycles when euploid blastocysts are transferred. Consequently, the question remains unanswered if the clinical pregnancy rates of single euploid FET with D5 or D6 blastocysts differ when the EP protocol remains constant.

Study design, size, duration

A single center observational study was performed between June 2017 and November 2020, including 1027 single euploid FET with blastocysts biopsied on D5 or D6. All patients with primary or secondary infertility who underwent a FET in a NC or HRT EP protocol, with blastocysts graded ≥ BL3CC (Gardner scoring system) prior to biopsy were included. Vitrified-warmed blastocysts that did not re-expand within 1-hour post-warming were excluded from the analysis.

Participants/materials, setting, methods

In NCs, vaginal progesterone (P4) (Endometrin®) was administrated (3x100mg) after endocrinological confirmation of ovulation until pregnancy test. For HRT cycles, oral estradiol administration was started on day 2 (4 mg) and increased to 6mg on D5 of the cycle. When endometrial thickness was ≥6 mm, P4 was given (3x100mg) until pregnancy test. All FET were performed on D5 after start of P4 administration. Clinical pregnancy was recorded as the presence of an intrauterine gestational sac.

Main results and the role of chance

Women’s mean age was 33.8 ± 5.5 years. A total of 651 FETs were performed with D5 euploid blastocysts (37.6% in NC and 62.4% in HRT) and 376 with D6 (43.1% in NC and 56.9% in HRT). Clinical pregnancy rate in NC was higher with D5 blastocysts compared to D6 (66.9% vs 50.0%; OR = 0.494, 95% CI = 0.322–0.758; p &lt; 0.001), while no significant differences were found when vitrified-warmed blastocysts were transferred in HRT cycles (64.3% vs 58.4%; OR = 0.781, 95% CI = 0.548–1.112; p = 0.164). Additionally, clinical miscarriage was significantly higher with D5 euploid blastocysts transferred in NC (D5=10.9% vs D6=3.7%, OR = 0.239, 95% CI = 0.044–0.837; p = 0.019). In HRT, miscarriage outcomes were similar between D5 and D6 euploid blastocysts (D5=18.7% vs D6=20.8%, OR = 0.781, 95% CI = 0.548–1.112; p = 0.164), but significantly higher (p &lt; 0.001) than in NC. From a multinomial logistic regression model including age, blastocyst quality and day of biopsy as confounding factors, the clinical pregnancy rate was significantly affected by D6 blastocyst biopsy (OR = 0.571, 95% CI = 0.360–0.906, p = 0.017) and inner cell mass (ICM) grade A (OR = 3.941, 95% CI = 1.149–10.402; p = 0.006) or B (OR = 2.601, 95% CI = 1.146–5.907, p = 0.022) in NC. In HRT cycles, exclusively ICM was statistically significant (OR = 2.555, 95% CI = 1.214–5.381, p = 0.015 and OR = 2.397, 95% CI = 1.286–4.470, p &lt; 0.001 for grade A and B, respectively).

Limitations, reasons for caution

The current results are based on an observational retrospective study. Live birth and perinatal outcomes should be considered in a further analysis to evaluate the performance of the NC vs HRT protocols when D5 or D6 euploid blastocysts are transferred in FET cycles.

Wider implications of the findings: While the clinical pregnancies of D5 and D6 euploid blastocysts are comparable in HRT protocols only, the miscarriage rates seem to be significantly increased as compared to NC. Further studies are required to personalize EP protocols based on the day of blastocyst biopsy in order to improve clinical outcomes.

Trial registration number

No

P–160 Sibling oocytes cultured in a time-lapse versus benchtop incubator: limited exposure of embryos outside the incubator improves outcomes

Study question

Does the limited exposure of embryos outside the incubator, during evaluation and changeover, have an impact on the blastocyst development, blastocyst quality and euploid outcomes?

Summary answer

Exposure of embryos outside the incubator, negatively impacts the number, quality and euploidy rate of day 5 blastocysts.

What is known already

The laboratory environment with its culture conditions is one of the crucial elements of the delicate equation to a successful ART outcome. It has been shown that increased fluctuations in the culture conditions have a considerable impact on the number of blastocysts obtained and cycle outcomes. Compared to conventional benchtop incubators, Time Lapse Technology (TLT) incubators capture images of the embryo and allow morphologic and morphokinetic assessment without disturbance during incubation. Several studies have been published comparing the efficiency, safety and outcome performance between conventional and TLT incubators, however, none of them explored the euploid outcomes.

Study design, size, duration

An observational sibling oocyte study was performed at ART Fertility Clinics, Abu Dhabi between March 2018 and April 2020 and included data of 796 mature oocytes injected from 42 stimulation cycles. Sibling oocytes were randomly split between 2 different incubators: 12 oocytes were assigned to the twelve wells of the EmbryoscopeTM (ES) and the remaining oocytes were cultured in a conventional benchtop incubator, G185 K-System (KS).

Participants/materials, setting, methods

Embryos from patients with primary or secondary infertility, who underwent ovarian stimulation for ICSI and PGT-A through NGS on trophectoderm biopsies, were eligible. All patients had at least 16 fresh mature oocytes, randomly allocated to two different incubators after ICSI: 503 (63.2%) oocytes were cultured in ES and 293 (36.8%) in KS. The fertilization, cleavage, useable blastocyst and euploid rates, as well as embryo/blastocyst qualities were assessed to evaluate each incubator’s performance.

Main results and the role of chance

The fertilization and cleavage rates were similar between incubators. Total useable blastocyst rate (64.8% vs 49.6%, p &lt; 0.001) was significantly higher for embryos cultured in ES, mainly due a higher percentage of blastocysts biopsied on day 5 in ES (67.8% vs 57.0%, p = 0.037), with improved quality (p = 0.008). There was no difference in the total euploid rate between ES and KS (59.9% vs 50.4%, p = 0.314), but a significantly higher euploid rate was seen for blastocysts cultured in ES and biopsied on day 5 (63.5% vs 37.4%, p = 0.001). Day 3 embryo quality and total biopsied blastocyst quality was not different between incubators. No difference was observed in the total useable blastocyst development from good (p = 0.0832) and poor (p = 0.112) quality day 3 cleavage stage embryos. However, when stratifying according to the day of blastocyst development, poor quality embryos on day 3 showed superior blastocyst formation on day 5 when cultured in ES (64.1% vs 39.1% for day 5 and 35.9% vs 60.9% for day 6, p = 0.005). Accordingly, blastocyst formation from poor quality embryos on day 3, was shifted to day 6 for embryos cultured in KS. This difference in the day of blastocyst development was not observed for good quality cleavage stage embryos (p = 0.917).

Limitations, reasons for caution

The current observational study needs confirmation in a prospective trial and should also include the implantation potential of the euploid blastocysts, which was not followed in the current study. A good prognosis population (≥16 mature oocytes) was studied and may not reflect the outcomes in patients with lower oocyte numbers.

Wider implications of the findings: This work builds evidence to the solid introduction of the TLT incubators to the clinical routine, as the reduced exposure of embryos outside the incubator – and hence decreased stress - improves the blastocyst development.

Trial registration number

NA

P–359 Blastocyst quality, transfer difficulty and endometrial thickness affect clinical pregnancy after frozen embryo transfer (FET) of euploid blastocysts in the upper uterine cavity

Study question

Which factors affect the clinical pregnancy rate (CPR) after single euploid frozen embryo transfers (FET), when the blastocyst is transferred in the upper uterine cavity area?

Summary answer

Blastocyst quality, embryo transfer difficulty and endometrial thickness affect the CPR in FET.

What is known already

There is a limited understanding of the factors affecting success rates after FET. The most important factors influencing implantation rates are patient characteristics, type of endometrial preparation, embryo quality and transfer difficulty. It has been shown that the position of the euploid blastocyst, measured as distance from the fundus (DFF) of the uterine cavity (mm), affects the implantation potential. Although the ideal location within the uterine cavity is still being debated in very heterogeneous patient populations, most studies have found that the highest pregnancy rates are obtained when the embryo is placed in the upper area of the uterine cavity.

Study design, size, duration

This single center retrospective cohort study included a total of 603 single euploid FET cycles, in the upper half of the uterine cavity, between January 2019 and November 2020 in ART Fertility Clinic Abu Dhabi, UAE.

Participants/materials, setting, methods

Trophectoderm biopsy samples were subjected to Next Generation Sequencing to screen the ploidy state. Vitrification and warming were performed using the Cryotop method (Kitazato, Biopharma). The full length of the uterine cavity and the longitudinal distance between the fundal endometrial surface and the air bubble after transfer were measured.

Main results and the role of chance

The patients were on average 33.9 (19–46) years old. The FET was performed in a natural cycle (NC) (n = 278) or hormone replacement therapy (HRT) (n = 325). Of the 603 transfers which had been performed in the upper half of the uterus, 412 (68.3%) resulted in a pregnancy and 311 (51.5%) in a clinical pregnancy. After bivariate analysis, the clinical pregnancy rate was significantly higher for high quality blastocysts (grade 1–2 versus 3–4) (p &lt; 0.001), after easy embryo transfers (p = 0.001) and for higher endometrial thickness (p = 0.027).

After performing a multivariate logistic regression analysis to consider the effect of all explanatory variables (age, Anti Müllerian hormone, body mass index, endometrial thickness, quality of the blastocyst, difficulty of the transfer [requirement of additional instrumentation], presence of mucus or blood on the transfer catheter, day 5 or day 6 biopsy, FET endometrial preparation), the clinical pregnancy was affected by the endometrial thickness: OR 1.20 [1.05–1.37], p = 0.007; transfer difficulty: OR 0.44 [0.25–0.79], p = 0.006; blastocyst quality 3: OR 0.38 [0.18–0.79], p = 0.01 and blastocyst quality 4: OR 0.15 [0.06–0.37], p &lt; 0.0001. Age did not affect the clinical pregnancy after transferring a single euploid blastocyst: OR 1.03 [1.00–1.06], p = 0.052.

Limitations, reasons for caution

The limitation of this study was its retrospective nature and the small sample size. Other parameters may be important in live birth outcomes.

Wider implications of the findings: Optimization of clinical pregnancy outcomes after FET depends on multiple factors. Even after transfer of euploid blastocysts in the upper uterine cavity, the endometrial thickness, transfer difficulty and blastocyst quality will still affect the clinical pregnancy outcomes.

Trial registration number

NA

P–271 Should intracytoplasmic sperm injection (ICSI) of delayed mature oocytes become a routine practice in the IVF Laboratory?

Study question

Do delayed mature oocytes result in similar euploid blastocyst rates as their immediate mature sibling oocytes?

Summary answer

Once a blastocyst is obtained, delayed mature oocytes have similar euploid rates compared to immediate mature oocytes.

What is known already

Intracytoplasmic sperm injection (ICSI) of metaphase II oocytes few hours post oocyte retrieval is standard practice in IVF laboratories. Immature metaphase I (MI) and prophase I (GV) oocytes are usually discarded. Immature oocytes may mature overnight, after which ICSI can be performed. Studies demonstrated lower fertilization and blastulation rates for these delayed mature oocytes. However, live births have been reported from blastocysts transferred. The evidence available is not compelling, since most of the studies had either low sample size, no preimplantation genetic testing for aneuploidies (PGT-A), or the outcome was not compared to sibling MII oocytes at time of denudation.

Study design, size, duration

A single-center retrospective sibling oocyte study was performed between January 2019 and December 2020 at ART Fertility clinics Abu Dhabi, UAE. A total of 345 PGT-A cycles, with at least one delayed mature oocyte inseminated by ICSI, were included: 2506 immediate mature oocytes and 669 delayed mature oocytes.

Participants/materials, setting, methods

Following controlled ovarian stimulation, MII oocytes at the time of denudation were inseminated by ICSI/IVF (immediate mature). Immature oocytes (MI/GV) were cultured for 16–24 hours in fertilization medium and injected the next day if matured (delayed mature). Trophectoderm biopsy was performed on day 5/6/7 and samples were subjected to Next Generation Sequencing to screen the ploidy state of the blastocyst.

Main results and the role of chance

The 345 controlled ovarian stimulation cycles resulted in the insemination of 2506 MII oocytes on the day of oocyte retrieval (Day0) and 669 delayed mature oocytes on day 1. Normal fertilization rate was significantly higher in the immediate mature oocytes compared to delayed mature oocytes (68% vs 56%, p &lt; 0.0001). Similarly, the usable blastocyst rate was significantly higher in immediate mature oocytes (59% vs 19%, p &lt; 0.0001). On day 5 of development, a significantly higher-good quality blastocyst formation rate was obtained from immediate mature oocytes (65% vs 27%, p &lt; 0.0001). The rate of good quality blastocyst on the day of biopsy was significantly higher in the immediate mature oocytes group (76% vs 62%, p &lt; 0.015).

Fisher’s Exact Test was performed to compare the euploid rate of blastocysts biopsied on day 5/6/7 originating from immediate mature oocytes or sibling delayed mature oocytes. The euploid potential of blastocyst biopsied showed no significant difference between the two groups (p = 0.388).

Limitations, reasons for caution

The timing of MI/GV oocytes transition to MII stage was not recorded since the incubation was done in a benchtop incubator. Furthermore, the same sperm sample was used to inseminate immediate and delayed mature oocytes, which might contribute to the compromised embryo development due to increased sperm DNA fragmentation.

Wider implications of the findings: Insemination of delayed mature oocytes by ICSI, should be considered as a tool to increase patients’ chances of obtaining a euploid embryo. Especially in cases where low yield of euploid embryos is expected.

Trial registration number

Not applicable

Intracytoplasmic sperm injection is not superior to conventional IVF in couples with non-male factor infertility and preimplantation genetic testing for aneuploidies (PGT-A)

STUDY QUESTION

Does the insemination method impact the euploidy outcome in couples with non-male factor infertility?

SUMMARY ANSWER

Conventional IVF can be applied in cycles with preimplantation genetic testing for aneuploidies (PGT-A), as both IVF and ICSI generate equal numbers of euploid blastocysts.

WHAT IS KNOWN ALREADY

Ever since its introduction, the popularity of ICSI has increased tremendously, even in couples with non-male factor infertility. The use of conventional IVF is a contraindication for couples undergoing PGT to ensure monospermic fertilisation and to eliminate potential paternal contamination from extraneous sperm attached to the zona pellucida. Despite this, it has recently been shown that sperm DNA fails to amplify under the conditions used for trophectoderm biopsy samples.

STUDY DESIGN, SIZE, DURATION

This single-centre prospective pilot study included 30 couples between November 2018 and April 2019.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Arab couples, with a female age between 18-40 years, body mass index ≤30 kg/m2, at least 10 cumulus oocyte complexes (COCs) following oocyte retrieval (OR) and normal semen concentration and motility (WHO) in the fresh ejaculate on the day of OR, were eligible for the study. Half of the sibling oocytes were assigned to conventional IVF, and the other half were assigned to ICSI. All embryos were cultured in a time-lapse imaging system in Global Total LP media. Blastocysts were subjected to trophectoderm biopsy on Day 5, 6 or 7 and next-generation sequencing (NGS) to determine blastocyst ploidy status. The primary objective was to determine the euploid rate in blastocysts from sibling oocytes.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 568 COCs were randomly allocated between IVF (n = 283; 9.4 ± 4.0) and ICSI (n = 285; 9.5 ± 4.1). While the incidence of normal fertilisation per cycle (6.1 ± 3.8 (64.0%) vs 6.3 ± 3.5 (65.4%); P = 0.609) was distributed equally between IVF and ICSI, the degeneration rate (0.1 ± 0.3 vs 0.7 ± 0.8; P = 0.0003) was significantly higher after ICSI and the incidence of abnormal fertilisation (≥3 pronuclei) was significantly higher after IVF (0.9 ± 1.2 vs 0.2 ± 0.4; P = 0.005). For all fertilised oocytes, there were no differences in the number of good-quality embryos on Day 3 (74% vs 78%; P = 0.467), nor in the blastulation rate on Day 5 (80.4% vs 70.8%; P = 0.076). The total number of blastocysts biopsied per cycle on Days 5, 6 and 7 was not significantly different between IVF or ICSI (4.0 ± 2.8 vs 3.9 ± 2.5; P = 0.774). With euploid rates of 49.8 and 44.1% (P = 0.755; OR: 1.05664 [0.75188-1.48494), respectively, there was no significant difference identified between IVF and ICSI (2.0 ± 1.8 vs 1.9 ± 1.7; P = 0.808) and all couples had at least one euploid blastocyst available for transfer. When considering only euploid blastocysts, the male/female ratio was 61/39 in IVF and 43/57 in ICSI (P = 0.063).

LIMITATIONS, REASON FOR CAUTION

This is a pilot study with a limited patient population of 30 couples (and 568 COCs) with a normal ovarian response. The results of our study should not be extrapolated to other patient populations.

WIDER IMPLICATIONS OF THE FINDINGS

It is safe to apply conventional IVF in couples with non-male factor infertility undergoing PGT-A.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was obtained. There are no competing interests.

TRIAL REGISTRATION NUMBER

NCT03708991.

Segmental duplications and monosomies are linked to in vitro developmental arrest

PURPOSE

To verify which genetic abnormalities prevent embryos to blastulate in a stage-specific time.

METHODS

A single center retrospective study was performed between April 2016 and January 2017. Patients requiring Preimplantation Genetic Testing for Aneuploidies (PGT-A) by Next Generation Sequencing (NGS) were included. All embryos were cultured in a time-lapse imaging system and single blastomere biopsy was performed on day 3 of development. Segmental duplications and deletions as well as whole chromosome monosomies and trisomies were registered. Embryo arrest was defined if the embryo failed to blastulate 118 h post-injection. A logistic regression model was applied using the time to blastulate as the response variable and the different mutations as explanatory variables. A p value < 0.05 was considered significant.

RESULTS

Of the 285 biopsied cleavage stage embryos, 103 (36.1%) were euploid, and 182 (63.9%) were aneuploid. There was a significant difference in the developmental arrest between euploid and aneuploid embryos (8.7% versus 42.9%; p = 0.0001). Segmental duplications and whole chromosome monosomies were found to have a significant effect on developmental arrest (p = 0.0163 and p = 0.0075), while trisomies and segmental deletions had no effect on developmental arrest. In case of segmental duplications, an increase of one extra segmental duplication increases the odd of arrest by 159%. For whole chromosome monosomies, the odd will only increase by 29% for every extra chromosomal monosomy. Both chromosomal abnormalities remained significant after adding age as an explanatory variable to the model (p = 0.014 and p = 0.009).

CONCLUSION

Day 3 cleavage stage embryos with segmental duplications or monosomies have a significantly decreased chance to reach the blastocyst stage.

Does blastocyst mitochondrial DNA content affect miscarriage rate in patients undergoing single euploid frozen embryo transfer?

PURPOSE

To determine whether the blastocyst mitochondrial DNA (mtDNA) content is related to the miscarriage rate in patients undergoing single euploid frozen embryo transfer (SEFET).

METHODS

A total of 355 single euploid frozen embryo transfer cycles were studied retrospectively between April 2017 and December 2018. A trophectoderm biopsy was performed on day 5/6 blastocysts. Post next-generation sequencing (NGS), the mtDNA content was calculated as the ratio of mitochondrial DNA over nuclear DNA, and the association between blastocyst mtDNA content and miscarriage rate was evaluated.

RESULT(S)

Three hundred fifty-five euploid blastocysts were selected for SEFET in 314 patients with an average age of 33.7 ± 5.6 years; 255 were biopsied on day 5 (71.8%) and 100 on day 6 (28.2%). Frozen embryo transfer (FET) was performed either in a hormone replacement therapy (HRT) cycle (71.8%; n = 255) or in a natural cycle (NC) (28.2%; n = 100). A pregnancy rate of 66.2% (235/355) was obtained with clinical pregnancy and miscarriage rates of 52.4% (n = 186) and 5.6% (n = 20), respectively. There was no significant difference neither between the blastocyst mtDNA content of pregnant and nonpregnant patients (27.7 ± 9.2 vs. 29.4 ± 8.6, P = 0.095) nor between patients with a clinical pregnancy and miscarriage (30.5 ± 9.3 vs. 27.3 ± 9.2, P = 0.136). Multivariate logistic regression analysis showed the same nonsignificant relationship, except for the miscarriage rate and BMI (OR 1.149, 95% CI 1.03-1.28; P = 0.012).

CONCLUSION(S)

Mitochondrial DNA content is unable to predict the miscarriage of implanted human euploid blastocysts.

Ethnic and Sociocultural Differences in Ovarian Reserve: Age-Specific Anti-Müllerian Hormone Values and Antral Follicle Count for Women of the Arabian Peninsula

BACKGROUND

Anti-Müllerian hormone (AMH) and antral follicle count (AFC) age-specific reference values form the basis of infertility treatments, yet they were based upon studies performed primarily on Caucasian populations. However, they may vary across different age-matched ethnic populations. This study aimed to describe age-specific serum AMH and AFC for women native to the Arabian Peninsula.

METHODS

A retrospective large-scale study was performed including 2,495 women, aged 19 to 50 years, native to the Arabian Peninsula. AMH and AFC were measured as part of their fertility assessment at tertiary-care fertility centres. Age-specific values and nomograms were calculated.

RESULTS

2,495 women were evaluated. Mean, standard deviation and median values were calculated for AMH and AFC by 1-year and 5-years intervals. Median age was 34.81 years, median AMH was 1.76ng/ml and median AFC was 11. From the total group, 40.60% presented with AMH levels below 1.3ng/mL. For women <45 years old, the decrease in AFC was between -0.6/-0.8 per year. Up to 36 years old, the decrease of AMH was 0.1ng/ml. However, from 36 to 40 years old, an accelerated decline of 0.23ng/ml yearly was noted. In keeping with local customs, 71.23% of women wore the hijab and 25.76% the niqab. AMH and AFC were significantly lower for niqab group compared with hijab group (p=0.02 and p=0.04, respectively).

CONCLUSION

This is to-date the largest data set on age-specific AMH and AFC values in women from the Arabian Peninsula aiming to increase clinical awareness of the ovarian reserve in this population.

Blastocyst mitochondrial DNA (mtDNA) is not affected by oocyte vitrification: a sibling oocyte study

PURPOSE

To evaluate whether mtDNA content at the blastocyst stage differs between embryos derived from fresh or vitrified sibling oocytes.

MATERIAL AND METHODS

A retrospective analysis was performed between March 2017 and September 2018, including 504 blastocysts from 94 couples undergoing preimplantation genetic testing for aneuploidies (PGT-A), using fresh oocytes together with previously vitrified oocytes. Trophectoderm biopsies were performed and subjected to next generation sequencing.

RESULTS

On average, 1.8 ± 1.0 oocyte vitrification cycles were performed per patient. Between fresh and vitrified cycles, no difference was observed between the number of fertilized oocytes (5.3 ± 4.2 versus 5.5 ± 3.0). Blastulation rate on day 5 per fertilized oocyte was significantly higher in the fresh group (62% ± 29% versus 44% ± 31%; p < 0.001). For the 504 biopsied blastocysts, 294 fresh versus 210 vitrified, no significant differences were found in the euploid rate, 40.5% versus 38.6% (p = 0.667), and mtDNA content, 30.1 (± 10.6) versus 30.0 (± 12.5) (p = 0.871), respectively. Regardless of the origin of the oocytes, aneuploid blastocysts contained significantly higher mtDNA values compared with the euploid ones (31.4 versus 28.0; p = 0.001). Furthermore, top-quality blastocysts had a significantly lower mtDNA content compared with moderate and poor-quality blastocysts (p < 0.001) and blastocysts biopsied on day 5 showed significantly lower mtDNA content compared with day 6 or day 7 blastocysts (p < 0.001). However, when analyzing the blastocyst mtDNA content according to the ploidy state, no differences were found for blastocyst quality or day of biopsy between blastocysts originating from fresh or vitrified oocytes.

CONCLUSION

Oocyte vitrification does not affect the mtDNA content of trophectoderm biopsies.

Anti-Müllerian hormone is an independent marker for oocyte survival after vitrification

RESEARCH QUESTION

This study explored the relationship between anti-Müllerian hormone (AMH) and oocyte survival after vitrification. The association between AMH and blastocyst formation after oocyte vitrification was also assessed.

DESIGN

A retrospective observational analysis was performed in a private IVF centre. A total of 4507 metaphase-II warmed oocytes were included from 450 couples, predominantly of Arab ethnicity. Between August 2015 and August 2018, couples underwent 484 intracytoplasmic sperm injection (ICSI) treatments using vitrified-warmed oocytes.

RESULTS

Patients' median age ± SD was 36.2 ± 6.1 years, AMH concentration 2.6 ± 3.4 ng/ml and body mass index (BMI) 26.5 ± 4.6 kg/m². The oocyte survival rate after vitrification was 87.37 ± 20.42%. AMH concentration showed a significant correlation (Kendall's tau 0.087, P = 0.0079) with oocyte survival rate independent of oocyte yield. Correlation was significant (odds ratio 1.041, 95% confidence interval 1.007-1.077, P = 0.018) when a multivariant model was applied that included AMH, age and BMI. The receiver operating characteristic curve showed an AMH cut-off value of 1.09 ng/ml that could obtain at least a 70% survival rate, with an area under the curve of 0.669. Regarding embryo development in ICSI cycles including fresh and warmed oocytes for the same patient, blastocyst formation rate was higher in fresh compared with warmed oocytes (P < 0.001). In this subgroup no significant correlation was seen between fertilization or blastocyst rate and AMH concentration.

CONCLUSIONS

AMH concentration showed a significant correlation with oocyte survival. Blastocyst formation was significantly lower after oocyte vitrification, but no correlation was found with AMH. Clinicians should carefully evaluate oocyte vitrification for patients with AMH below 1.09 ng/ml and consider embryo accumulation for these patients in preference to oocyte accumulation.

Vitamin D in Follicular Fluid Correlates With the Euploid Status of Blastocysts in a Vitamin D Deficient Population

CONTEXT

The widespread distribution of the Vitamin D (VitD) receptor in reproductive tissues suggests an important role for VitD in human reproduction. The assessment of patient´s VitD is based on the 25-hydroxyvitamin D (25(OH)D) metabolite measurement. However, most of the circulating 25(OH)D is bound to either VitD-binding protein (VDBP) (88%) or albumin (12%) and less than 1% circulates free.

OBJECTIVE

To determine a possible correlation between VitD levels in serum (S) and follicular fluid (FF) and blastocyst ploidy status in patients undergoing infertility treatment.

METHODS

A prospective observational study was performed including couples planned for preimplantation genetic testing for aneuploidies (PGT-A) from ART Fertility Clinics. Patients were classified according to their 25(OH)D-Serum levels: VitD deficient group <20 ng/ml and insufficient/replete ≥20 ng/ml defined as VitD non-deficient group.

RESULTS

Serum samples and 226 FF from individual follicles were collected for 25(OH)D, bioavailable 25(OH)D, free 25(OH)D, and % free 25(OH)D measurement. 25(OH)D-Serum in VitD deficient and non-deficient were 13.2±4.0 ng/ml vs 32.3±9.2 ng/ml; p<0.001. FF from 40 and 74 biopsied blastocysts was analysed of which 52.5 and 60.8% were euploid (p = 0.428), respectively. In VitD deficient patients, mean 25(OH)D-FF, bioavailable 25(OH)D-FF, and free 25(OH)D-FF were higher in euploid vs aneuploid blastocysts (18.3±6.3 ng/ml vs 13.9±4.8 ng/ml; p = 0.040; 1.5±0.5 ng/ml vs 1.1±0.4 ng/ml; p = 0.015; 0.005±0.002 ng/ml vs 0.003±0.001 ng/ml; p = 0.023, respectively), whilst no differences were found in VitD non-deficient patients (37.9±12.3 ng/ml vs 40.6±13.7 ng/ml; p = 0.380; 3.1±1.1 ng/ml vs 3.3±1.2 ng/ml; p = 0.323; 0.01±0.003 ng/ml vs 0.01±0.004 ng/ml; p = 0.319, respectively).

CONCLUSION

VitD non-deficient patients have a significantly higher probability of obtaining a euploid blastocyst compared to VitD deficient patients (OR:33.36, p = 0.002).

mtDNA dynamics between cleavage-stage embryos and blastocysts

PURPOSE

The aim was to evaluate mtDNA content and its dynamics in euploid and aneuploid embryos from cleavage to blastocyst stage following consecutive biopsies. The effect of female age on mtDNA content was evaluated by comparing reproductively younger (≤ 37 years) with older (> 37 years) women.

METHODS

A retrospective single-centre descriptive study was performed between August 2016 and January 2017. Forty patients, with 112 embryos, undergoing preimplantation genetic testing for aneuploidies (PGT-A) by next-generation sequencing (NGS) were included. Embryos that reached the blastocyst stage and were not selected for fresh embryo transfer were included following consecutive biopsies of a single blastomere on day 3 and trophectoderm biopsy of day 5 blastocysts.

RESULTS

Cleavage-stage mtDNA was significantly lower in fast cleaving embryos (p = 0.016). Based on the concordance between day 3 and day 5 biopsies, a difference was identified in blastocyst mtDNA content between groups (p = 0.019); true euploid blastocysts presented a lower mtDNA content. No association was identified between cleavage-stage mtDNA content and ploidy status (OR 1.008 [0.981-1.036], p = 0.565) nor between blastocyst mtDNA content and ploidy outcome (OR 0.954 [0.898-1.014], p = 0.129). No difference was found when comparing mtDNA content and ploidy outcome between the two reproductive age groups (p = 0.505 (cleavage stage) and p = 0.774 (blastocyst)).

CONCLUSION

Mitochondrial DNA content of cleavage-stage embryos and blastocysts is unable to predict ploidy status. Subgroup analysis based on ploidy concordance between day 3 and day 5 revealed a significantly lower mtDNA content for true euploid blastocysts. Reproductive ageing does not affect mtDNA content.

Cleavage stage mitochondrial DNA is correlated with preimplantation human embryo development and ploidy status

PURPOSE

To evaluate whether the mitoscore of cleavage stage embryos might correlate with developmental kinetics and the ploidy status.

MATERIALS

This retrospective single-center study involved all cycles between April 2016 and April 2018 in which preimplantation genetic testing for aneuploidy (PGT-A) on day 3 was performed. The mitochondrial DNA (mtDNA) content and embryo ploidy were determined on 375 single blastomere biopsies by next generation sequencing (NGS). After intracytoplasmic sperm injection, a time-lapse imaging system (embryoscope) was used to follow the development. The median mtDNA content of cleavage stage embryos (49.4) was used to stratify the embryos into two groups to compare embryo development and ploidy status: low mitoscore group (≤ 49.4) and high mitoscore group (> 49.4).

RESULTS

The total number of euploid embryos was equal between both mitoscore groups (32.1% versus 33.5%; p = 0.854). However, embryos in the low mitoscore group had a significantly higher cell number on day 3 (8.13 ± 1.59 versus 7.62 ± 1.5; p = 0.0013) and showed a significantly faster development up until the 8-cell stage. Mitoscore was not different between euploid and aneuploid embryos, with the same blastomere number at the time of biopsy. Furthermore, absence of cavitation within 118 h after insemination was correlated with higher mitoscore values (60.22 ± 42.23 versus 50.97 ± 13.37; p = 0.006) and a lower chance of being euploid (17.1% versus 47.4%; p = 0.001).

CONCLUSION

mtDNA content of cleavage stage embryos correlates with time-lapse parameters. Early blastulation is correlated with a lower mtDNA content and a higher chance of euploidy.

Clinical reassessment of human embryo ploidy status between cleavage and blastocyst stage by Next Generation Sequencing

One of the most important limitations of genetic testing in preimplantation embryos is embryonic mosaicism, especially when performed on D3 with only a single blastomere evaluated. Previous publications, using Array-Comparative Genomic Hybridization (a-CGH) to compare day 3 (D3) biopsies versus trophectoderm biopsies for the analysis of aneuploid embryos, showed similar high concordance rates per embryo diagnosis for D3 biopsies and trophectoderm biopsies. Next generation sequencing (NGS) was introduced lately as a new technique for preimplantation genetic testing for aneuploidies (PGT-A). Using this technique, this retrospective descriptive study evaluated the degree of the concordance of the diagnosis between preimplantation human cleavage stage (D3) and blastocyst stage (D5) embryos. Double biopsies on D3 and D5 were performed on 118 embryos, reaching blastocyst stage on D5 and had not been selected for transfer. As the fertilization law of the United Arab Emirates does not allow embryo freezing, also surplus euploid embryos after D 3 biopsy were included. Analysis of the NGS results from D3 and D5 embryo biopsies showed a total concordance rate per embryo diagnosis of 85.6% for euploid and aneuploid embryos. The concordance rates per embryo chromosomal pattern for embryo diagnosed as aneuploid at both biopsy stages was 82.2%. However, the status regarding the affected chromosomes was not identical on D3 and D5. Hence, the total concordance rate between D3 biopsy and D5 biopsy was limited to 67.8%. This current study clearly demonstrated that the concordance rates between D3 and D5 biopsies in aneuploid and euploid embryos are lower than previously reported.