Preimplantation Genetic Testing For Aneuploidy Research Articles

Is a day 7 blastocyst predictive of the reproductive potential of sibling day 5 and day 6 blastocysts?

To explore if a day 7 blastocyst is predictive of the reproductive potential of sibling day 5 or day 6 blastocysts? Retrospective cohort of autologous frozen embryo transfers (FET), February 2019 to April 2022. Cycles divided into groups 1 to 5, according to the day of embryo cryopreservation and the presence of a day 7 blastocyst sibling within the cohort: group 1/group 2-day 5 blastocyst without/with a day 7 sibling, group 3/group 4-day 6 blastocyst without/with a day 7 sibling, group 5-day 7 blastocyst. Clinical, ongoing pregnancy and miscarriage rates, cycle, and patient characteristics are reported. Multivariable generalized estimating equations (GEE) logistic regression analysis accounts for confounders and assesses the effect of a sibling day 7 blastocyst on ongoing pregnancy rates of day 5 or day 6 blastocyst FETs. Ongoing pregnancy rates are 38.4%, 59.5%, 30.8%, 32.7%, and 4.4% in groups 1-5, respectively. When correcting for maternal age, number of oocytes retrieved and discarded per cohort, and ploidy, embryos cryopreserved on either day 6 or day 7 have reduced odds of ongoing pregnancy after FET compared to day 5 blastocysts (OR = 0.76, IQR [0.61-0.95], p-value = 0.01). However, the presence of a day 7 sibling does not significantly affect odds of ongoing pregnancy of day 5 or day 6 blastocysts compared to the same-day blastocyst without a day 7 sibling (p-value = 0.20 and 0.46, respectively). This finding is consistent within both the Preimplantation Genetic Testing for Aneuploidy (PGT-A) unscreened and screened (euploid) embryo subgroups. Day of embryo cryopreservation significantly affects ongoing pregnancy rates. However, day 7 embryos within a cohort do not affect the reproductive potential of sibling day 5 and day 6 blastocysts, suggesting that slow embryo development is an embryo-specific trait.

Effect of intraovarian platelet-rich plasma injection on IVF outcomes in women with poor ovarian response: the PROVA randomized controlled trial.

Does intraovarian platelet-rich plasma (PRP) injection increase the number of mature oocytes obtained after controlled ovarian stimulation (COS) in young women with poor ovarian response (POR) undergoing IVF? Intraovarian PRP injection procedure does not improve mature oocyte yield after COS in women less than 38 years old with an established IVF history of POR. POR is frequently encountered among the infertile population and the number of women seeking infertility treatment related to POR is increasing. Effective treatment options for this patient population to conceive with autologous oocytes are lacking. Case series and cohort studies suggest that intraovarian PRP injection may improve follicular recruitment in women with premature ovarian insufficiency (POI) and POR, yet robust randomized studies have not been performed to date to determine the clinical utility of this intervention. This was a multi-center randomized controlled trial (RCT) conducted at university-affiliated reproductive centers in the USA and Turkey, between January 2020 and November 2022. Patients who met inclusion criteria (<38 years old, two or more prior cycles with <3 oocytes retrieved; and without single gene disorders, prior ovarian surgery, endometriomas, BMI >35 kg/m2, or severe male factor infertility) were randomized to either the PRP or control group. Patients in both groups subsequently underwent COS, oocyte retrieval, ICSI, preimplantation genetic testing for aneuploidy (PGT-A), and single euploid embryo transfer. Number of metaphase II (MII) oocytes obtained was the primary outcome. Secondary outcomes included ovarian reserve tests (antral follicle count [AFC] and anti-Müllerian hormone [AMH]), blastocyst and euploid blastocyst yields, and sustained implantation. The study was powered to detect a difference of one mature oocyte obtained at oocyte retrieval. In total, 83 patients met inclusion criteria and were randomized to receive autologous intraovarian PRP injection (n = 41) or to no intervention (n = 42). No significant differences were observed in number of MII oocytes retrieved per cycle (2.8 ± 2.4 vs 3.1 ± 3.3 in PRP vs control, respectively; P = 0.9), blastocysts (1.0 ± 1.3 vs 1.3 ± 2.1, P = 0.8), or euploid blastocysts (0.8 ± 1.1 vs 0.9 ± 1.6; P = 0.5). Similarly, no differences were observed in the likelihood of obtaining at least one euploid blastocyst (45% vs 37%, P = 0.4; relative risk [RR], 95% CI = 0.9, 0.6-1.2) or the rate of sustained implantation (31% vs 29%, P = 0.9; RR 1.0, 0.7-1.3). Posttreatment AFC (7.9 ± 4.5 vs 6.8 ± 4.8, P = 0.3) and AMH (0.99 ± 0.98 vs 0.7 ± 0.6, P = 0.2) were also not different between the groups. Results from this RCT may not be generalizable to other PRP preparations owing to heterogeneity and lack of standardization. The control groups did not undergo a sham ovarian injection, which would have been relevant had the results shown benefit of PRP injection. Only patients with POR were included in this study, and these results may not be generalizable to more severe diminution of ovarian reserve, as seen with POI. The intraovarian PRP injection procedure does not improve mature oocyte yield or other parameters of IVF outcome in women less than 38 years old with an established IVF history of POR. The results from this study do not support the use of intraovarian PRP injection in this population. Departmental funds were used and no external funding was requested for this study. ES is a consultant for and receives grant funding from the Foundation for Embryonic Competence. All other authors have no conflict of interest to declare. Clinicaltrials.gov Registry Identifier: NCT04163640. 15 November 2019. 24 February 2020.

The comparision among euploidy of preimplantation blastocysts in different controlled ovary stimulation (COH) protocols.

To compare differences in euploidy rates for blastocysts in preimplantation genetic testing for aneuploidy (PGT-A) cycles after gonadotropin-releasing hormone agonist (GnRH-a) long and short protocols, GnRH-antagonist (GnRH-ant) protocol, progestin-primed ovarian stimulation and mild stimulation protocols, and other ovary stimulation protocols. This was a retrospective cohort study from the Assisted Reproductive Medicine Department of Shanghai First Maternity and Infant Hospital. A total of 1657 PGT-A cycles with intracytoplasmic sperm injection after different controlled ovary hyperstimulation protocols were analyzed, and a total of 3154 embryos were biopsied. Differences in euploidy rate per embryo biopsied, embryo euploidy rate per oocyte retrieved and cycle cancellation rate were compared. For the PGT-A cycles, the euploidy rate per embryo biopsied was lower in the GnRH-ant protocol than in the GnRH-a long protocol (53.26 vs. 58.68%, respectively). Multiple linear regression showed that the GnRH-ant protocol was associated with a lower euploidy rate per embryo biopsied (β =  -0.079, p = 0.011). The euploidy rate per embryo biopsied was not affected by total gonadotropin dosage, duration of stimulation and number of oocytes retrieved. The embryo euploidy rate per oocyte retrieved was similar in all protocols and was negatively correlated with the total number of oocytes retrieved (β =  -0.003, p = 0.003). Compared with the GnRH-a long protocol, the GnRH-ant protocol was associated with a lower euploidy rate per embryo biopsied. The total gonadotropin dosage, duration of stimulation and number of oocytes retrieved did not appear to significantly influence euploidy rates.

Abstract PO4-11-10: Comparison of frozen embryo transfer cycle (FET) outcomes between young women with breast cancer (YWBC) with and without pathogenic variants (PV), and breast cancer-free PV carriers

Abstract BACKGROUND: In vitro fertilization (IVF) and preimplantation genetic testing for aneuploidy (PGT-A) and monogenic disorders (PGT-M) are valuable tools for YWBC with or without PV such as BRCA1/2, ATM, CHEK2, PMS2 to prevent variant transmission to offspring.  However, to date, there is scarce data on the usability of these cryopreserved, tested embryos and on the outcomes of FET cycles within the cancer population. It has been suggested that PV may influence endometrial thickness which is associated with embryo implantation and ultimately FET success rates. Thus, this study aimed to compare reproductive outcomes of FET cycles between YWBC with an identified PV, breast cancer (BC) patients without a PV, and cancer-free PV-carriers who returned to use their cryopreserved oocytes or embryos derived from IVF ± PGT-A/M cycles. METHODS: Patients that underwent either fertility preservation (FP) prior to BC therapy or preventative IVF/PGT-A/M cycles from 2009-2023 were included. All IVF &amp; PGT-A/M was performed at academic IVF centre. Genetic testing was conducted using high resolution next generation sequencing on the Illumina platform. We compared reproductive outcomes between 3 groups: 1) YWBC with a known PV (BCPV), 2) YWBC without a PV (BCNV), 3) Cancer-free patients who had a PV (CFPV). Primary outcomes measured were endometrial thickness, and FET success rates (i.e., ongoing pregnancy or live birth) analyzed by chi-square, t-tests and ANOVA. RESULTS: 185 patients underwent 202 cycles for either oocyte or embryo freezing. Mean age was 33.8±4.6 years (range 21-45) and mean BMI was 24.6±5.0 kg/m2 (range 15.7-42.7). 64 patients had a PV including BRCA1 (n=22), BRCA2 (n=20) and others (n=22): ATM, BARD1, BRIP1, CHEK2, MLH1, P53, PALB2, PDL2, PMS2, PTCH1, &amp; RAD51D. When comparing the BCPV, BCNV &amp; CFPV groups, no significant differences were found in the mean age (33.7 ± 4.9 vs. 36.8 ± 4.3 vs. 34.3 ± 4.4 years, p=0.52), mean BMI (26.2 ± 4.9 vs. 24.3 ± 4.8 vs. 24.3 ± 4.8 kg/m2, p=0.13), and the proportion of smokers (23.1% vs. 35.0% vs. 36.4%, p=0.72). Only 60% of BCNV performed PGT-A due to their lack of PV. As of June 2023, 44 patients (12 in BCPV, 20 in BCNV, and 12 in CFPV) returned to undergo 81 FET cycles (range 1-5/patient). 12/81(14.8%) FETs involved a surrogate. When comparing the BCPV, BCNV &amp; CFPV who had FET, a significant difference was found in the mean age at oocyte retrieval between BCPV &amp; BCNV (32.9±4.4 vs. 37.0±4.0 years, p=0.001) but not with CFPV (33.5±4.4 years). The endometrial thickness at the time of FET between the BCPV, BCNV, and CFPV groups was similar (10.2±1.6 vs. 10.6±2.6 vs. 9.3±1.9 mm, p=0.12), as was the proportion of smokers (25.0% vs. 36.8% vs. 33.3%, p=0.79). YWBC had a mean delay from egg retrieval to their first FET of 37 months. Estrogen receptor positive (ER+) YWBC had a longer delay than ER- patients (40.1±23.8 months vs. 29.6±11.6 months, p=0.25). 29/44 (65.9%) had at least one successful FET and another 5 YWBC conceived naturally or with intrauterine insemination (IUI); the cumulative pregnancy rate was 77.3% (34/44). The clinical pregnancy rate of 81 FETs was 44.4%. The BCPV group (73.7%) had a significantly higher successful outcome than the BCNV (35.3%) and CFPV (35.7%) groups (p=0.01). CONCLUSIONS: FP done at the time of a BC diagnosis is an effective tool to preserve fertility potential. 77% of patients had at least one baby from either IVF, IUI or conceived naturally. We did not find a difference in endometrial thickness in PV carriers. While all YWBC had a delay to their first FET from the time of their retrieval, those who were ER+ had a longer delay than ER- because of their need for endocrine therapy. The BCPV group had the highest FET success rate which is likely due to their younger age and use of PGT-A/M thereby eliminating FETs of abnormal embryos that would fail to implant. The BCNV were older with more untested embryos. The CFPV group transferred euploid embryos and thus the lower success rate is puzzling and needs further investigation. Citation Format: Maya Sharon-Weiner, Amanda Kauffman, Adina Tanen, Samantha Yee, Svetlana Madjunkova, Karen Glass. Comparison of frozen embryo transfer cycle (FET) outcomes between young women with breast cancer (YWBC) with and without pathogenic variants (PV), and breast cancer-free PV carriers [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-11-10.

Culture time to optimize embryo cell-free DNA (cfDNA) analysis for frozen-thawed blastocysts undergoing non-invasive preimplantation genetic testing for aneuploidy (niPGT-A)

Cell-free DNA (cfDNA) is released into the spent blastocyst media (spent media) by the embryo. However, optimal timing to determine maximal cfDNA in the case of frozen-thawed blastocysts undergoing non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) remains to be elucidated. In the current study we investigated the ideal time in culture to optimize embryo cell-free DNA (cfDNA) analysis in frozen-thawed blastocysts undergoing niPGT-A. In this prospective observational study, 135 spent media and corresponding whole blastocysts were collected from January 2021 through March 2022. Day-5 frozen-thawed blastocysts were cultured for 8 hours (Day-5 Short) or 24 hours (Day-5 Long), while day-6 frozen-thawed blastocysts were cultured for 8 hours (Day-6 Short). The spent media and whole blastocysts were then collected for further analysis. Spent media and whole blastocysts were amplified using whole genome amplification (WGA) and sequenced using Next Generation Sequencing (NGS). Informativity and concordance rates between cfDNA in spent media and whole blastocysts DNA were compared according to the different time in culture. When comparing time in culture, informativity rates for spent media were significantly higher (p<0.0001) for Day-5 Long and Day-6 Short (>91%) compared to the Day-5 Short group (<60%). A similar trend was observed for cases with and without a previous PGT-A. Regarding blastocyst expansion grade, informativity rates were lower in Day-5 Short, compared to Day-5 Long and Day-6 Short, regardless of expansion degree. This decrease was significant for Gardner grade expansion grade 3 (p=0.0005), 4 (p=0.0366) and 5-6 (p=0.0002). In addition, for a similar time in culture, the grade of expansion did not have an impact on the informativity rates. For concordance rates, no significant differences were observed among the three groups. In all cases concordance rates were 90.5% for Day-5 Short, 93.6% for Day-5 Long and 92.3% for Day-6 Short. No impact of the expansion grade was observed on concordance rates. niPGT-A in frozen-thawed blastocysts yields very high concordance rates with whole blastocysts, possibly limiting the need for invasive PGT-A and making it available for a wider range of patients.

[Analysis of related factors influencing the detection rate of mosaic embryo and the pregnancy outcomes with mosaic embryo transfers].

Objective: To explore the related factors influencing the detection rate of mosaic embryo and the pregnancy outcomes of mosaic embryo transfer in preimplantation genetic testing for aneuploidy (PGT-A) based on next generation sequencing (NGS) technology. Methods: A retrospective study was performed to analyze the clinical data of patients in 745 PGT-A cycles from January 2019 to May 2023 at Chongqing Health Center for Women and Children, including 2 850 blastocysts. The biopsy cells were tested using NGS technology, and the embryos were divided into three groups based on the test results, namely euploid embryos, aneuploid embryos and mosaic embryos. The influence of population characteristics and laboratory-related parameters on the detection rate of mosaic embryo were analyzed, and the pregnancy outcomes of 98 mosaic embryo transfer cycles and 486 euploid embryo transfer cycles were compared during the same period, including clinical pregnancy rate and live birth rate. Results: Among the embryos tested (n=2 850), the number and proportion of euploid embryos, aneuploid embryos and mosaic embryos were 1 489 (52.2%, 1 489/2 850), 917 (32.2%, 917/2 850) and 444 (15.6%, 444/2 850), respectively. Among mosaic embryos, 245 (55.2%, 245/444) were segmental mosaic embryos, 118 (26.6%, 118/444) were whole-chromosome mosaic embryos, and 81 (18.2%, 81/444) were complex mosaic embryos. NGS technology was performed in 4 genetic testing institutions and the detection rate of mosaic embryo fluctuated from 13.5% to 27.0%. The distributions of female age, level of anti-Müllerian hormone, PGT-A indications, ovulation-inducing treatments, gonadotropin (Gn) dosage, Gn days, inner cell mass grade, trophectoderm cell grade, genetic testing institutions and developmental stage of blastocyst were significantly different among the three groups (all P<0.05). Multi-factor analysis showed that the trophectoderm cell grade and genetic testing institutions were significantly related to the detection rate of mosaic embryo; compared with the trophectoderm cell graded as A, the detection rate of mosaic embryo was significantly increased in the trophectoderm cell graded as B-(OR=1.59, 95%CI: 1.04-2.44, P=0.033); compared with genetic testing institution a, the detection rate of mosaic embryo was significantly higher (OR=2.89, 95%CI: 2.10-3.98, P<0.001) in the testing institution c. The clinical pregnancy rate and live birth rate with mosaic embryos transfer were significantly lower than those of euploid embryos transfer (clinical pregnancy rate: 51.0% vs 65.2%, P=0.008; live birth rate: 39.4% vs 53.2%, P=0.017). After adjustment for age, PGT-A indications, trophectoderm cell grade and days of embryo culture in vitro, the clinical pregnancy rate and live birth rate with mosaic embryos transfer were significantly lower than those of euploid embryos transfer (clinical pregnancy rate: OR=0.52, 95%CI: 0.32-0.83, P=0.007; live birth rate: OR=0.50, 95%CI: 0.31-0.83, P=0.007). Conclusions: The trophectoderm cell grade and genetic testing institutions are related to the detection rate of mosaic embryo. Compared with euploid embryos transfer, the clinical pregnancy rate and live birth rate with mosaic embryos transfer are significantly reduced. For infertile couple without euploid embryos, transplantable mosaic embryos could be recommended according to the mosaic ratio and mosaic type in genetic counseling to obtain the optimal pregnancy outcome.

The severity of meiotic aneuploidy is associated with altered morphokinetic variables of mouse oocyte maturation

Abstract STUDY QUESTION Is there an association between morphokinetic variables of meiotic maturation and the severity of aneuploidy following in vitro maturation (IVM) in the mouse? SUMMARY ANSWER The severity of meiotic aneuploidy correlates with an extended time to first polar body extrusion (tPB1) and duration of meiosis I (dMI). WHAT IS KNOWN ALREADY Morphokinetic variables measured using time-lapse technology allow for the non-invasive evaluation of preimplantation embryo development within clinical assisted reproductive technology (ART). We recently applied this technology to monitor meiotic progression during IVM of mouse gametes. Whether there is a relationship between morphokinetic variables of meiotic progression and aneuploidy in the resulting egg has not been systematically examined at the resolution of specific chromosomes. Next-generation sequencing (NGS) is a robust clinical tool for determining aneuploidy status and has been reverse-translated in mouse blastocysts and oocytes. Therefore, we harnessed the technologies of time-lapse imaging and NGS to determine the relationship between the morphokinetics of meiotic progression and egg aneuploidy. STUDY DESIGN, SIZE, DURATION Cumulus–oocyte complexes (COCs) were collected from large antral follicles from hyperstimulated CD-1 mice. Cumulus cells were removed, and spontaneous IVM was performed in the absence or presence of two doses of Nocodazole (25 nM or 50 nM) to induce a spectrum of spindle abnormalities and chromosome segregation errors during oocyte meiosis. Comprehensive chromosome screening was then performed in the resulting eggs, and morphokinetic variables and ploidy status were compared across experimental groups (control, n = 11; 25 nM Nocodazole, n = 13; 50 nM Nocodazole, n = 23). PARTICIPANTS/MATERIALS, SETTING, METHODS We monitored IVM in mouse oocytes using time-lapse microscopy for 16 hours, and time to germinal vesicle breakdown (tGVBD), time to first polar body extrusion (tPB1), and duration of meiosis I (dMI) were analyzed. Following IVM, comprehensive chromosome screening was performed on the eggs and their matched first polar bodies via adaptation of an NGS-based preimplantation genetic testing for aneuploidy (PGT-A) assay. Bioinformatics analysis was performed to align reads to the mouse genome and determine copy number-based predictions of aneuploidy. The concordance of each polar body–egg pair (reciprocal errors) was used to validate the results. Ploidy status was categorized as euploid, 1–3 chromosomal segregation errors, or ≥ 4 chromosomal segregation errors. Additionally, aneuploidy due to premature separation of sister chromatids versus non-disjunction was distinguished. MAIN RESULTS AND THE ROLE OF CHANCE We applied and validated state-of-the-art NGS technology to screen aneuploidy in individual mouse eggs and matched polar bodies at the chromosome-specific level. By performing IVM in the presence of different doses of Nocodazole, we induced a range of aneuploidy. No aneuploidy was observed in the absence of Nocodazole (0/11), whereas IVM in the presence of 25 nM and 50 nM Nocodazole resulted in an aneuploidy incidence of 7.69% (1/13) and 82.60% (19/23), respectively. Of the aneuploid eggs, 5% (1/20) was due to premature separation of sister chromatids (PSSC), 65% (13/20) to non-disjunction (NDJ), and the remainder to a combination of both. There was no relationship between ploidy status and tGVBD, but tPB1 and the dMI were both significantly prolonged in eggs with reciprocal aneuploidy events compared to the euploid eggs, and this scaled with the severity of aneuploidy. Eggs with ≥4 aneuploid chromosomes had the longest tPB1 and dMI (p &amp;lt; 0.0001), whereas eggs with 1–3 aneuploid chromosomes exhibited intermediate lengths of time (p &amp;lt; 0.0001). LARGE SCALE DATA N/A LIMITATIONS, REASONS FOR CAUTION We used Nocodazole in this study to disrupt the meiotic spindle and induce aneuploidy in mouse oocytes. Whether the association between morphokinetic variables of meiotic progression and the severity of aneuploidy occurs with other compounds that induce chromosome segregation errors remain to be investigated. In addition, unlike mouse oocytes, human IVM requires the presence of cumulus cells, which precludes visualization of morphokinetic variables of meiotic progression. Thus, our study may have limited direct clinical translatability. WIDER IMPLICATIONS OF THE FINDINGS We validated NGS in mouse eggs to detect aneuploidy at a chromosome-specific resolution which greatly improves the utility of the mouse model. With a tractable and validated model system for characterizing meiotic aneuploidy, investigations into the molecular mechanisms and factors which may influence aneuploidy can be further elaborated. Time-lapse analyses of morphokinetic variables of meiotic progression may be a useful non-invasive predictor of aneuploidy severity. STUDY FUNDING/COMPETING INTERESTS This work was supported by the Bill &amp; Melinda Gates Foundation [INV-003385]. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. The authors have no conflict of interest to disclose.

Time-lapse imaging of morula compaction for selecting high-quality blastocysts: a retrospective cohort study.

Before blastocyst development, embryos undergo morphological and metabolic changes crucial for their subsequent growth. This study aimed to investigate the relationship between morula compaction and blastocyst formation and the subsequent chromosomal status of the embryos. This retrospective cohort study evaluated embryo development (n = 371) using time-lapse imaging; 94 blastocysts underwent preimplantation genetic testing for aneuploidy (PGT-A). The embryos were classified as fully (Group 1, n = 194) or partially (Group 2, n = 177) compacted. Group 1 had significantly higher proportions of good- and average-quality blastocysts than Group 2 (21.6% vs. 3.4%, p = 0.001; 47.9% vs. 26.6%, p = 0.001, respectively). The time from the morula stage to the beginning and completion of compaction and blastocyst formation was significantly shorter in Group 1 than in Group 2 (78.6 vs. 82.4h, p = 0.001; 87.0 vs. 92.2h, p = 0.001; 100.2 vs. 103.7h, p = 0.017, respectively). Group 1 embryos had larger surface areas than Group 2 embryos at various time points following blastocyst formation. Group 1 blastocysts had significantly higher average expansion rates than Group 2 blastocysts (653.6 vs. 499.2μm2/h, p = 0.001). PGT-A revealed a higher proportion of euploid embryos in Group 1 than in Group 2 (47.2% vs. 36.6%, p = 0.303). Time-lapse microscopy uncovered a positive relationship between compaction and blastocyst quality and its association with embryo ploidy. Hence, compaction evaluation should be prioritized before blastocyst selection for transfer or cryopreservation.

Leukocytospermia does not negatively impact outcomes in in vitro fertilization cycles with intracytoplasmic sperm injection and preimplantation genetic testing for aneuploidy: findings from 5435 cycles.

To investigate whether leukocytospermia (defined as the presence of ≥ 1 × 106 white blood cells/mL) affects clinical and embryologic outcomes in in vitro fertilization (IVF) cycles with intracytoplasmic sperm injection (ICSI) and preimplantation genetic testing for aneuploidy (PGT-A). This was a retrospective cohort study including 5425 cycles between January 2012 to December 2021 at a single large university-affiliated fertility clinic. The primary outcome was live birth rate (LBR). The prevalence of leukocytospermia was 33.9% (n = 1843). Baseline characteristics including female age, BMI, AMH, Day 3 FSH, and male partner's age were similar in cycles with and without leukocytospermia. The LBR after the first euploid embryo transfer was similar in those with and without leukocytospermia (62.3% vs. 63% p = 0.625). Secondary outcomes including clinical pregnancy rate (CPR), sustained implantation rate (SIR), fertilization (2PN) rate, blastulation rate, and aneuploidy rate were also evaluated. The CPR (73.3% vs 74.9%, p = 0.213) and SIR (64.6% vs. 66%, p = 0.305) were similar in both groups. The 2PN rate was also similar in both groups (85.7% vs. 85.8%, p = 0.791), as was the blastulation rate per 2PN (56.7% vs. 57.5%, p = 0.116). The aneuploidy rate was not significantly different between groups (25.7% vs 24.4%, p = 0.053). A generalized estimation equation with logistic regression demonstrated that the presence leukocytospermia did not influence the LBR (adjusted OR 0.878; 95% CI, 0.680-1.138). Leukocytospermia diagnosed just prior to an IVF cycle with PGT-A does not negatively impact clinical or embryologic outcomes.

Aneuploidy detection in pooled polar bodies using rapid nanopore sequencing.

Various screening techniques have been developed for preimplantation genetic testing for aneuploidy (PGT-A) to reduce implantation failure and miscarriages in women undergoing in vitro fertilisation (IVF) treatment. Among these methods, the Oxford nanopore technology (ONT) has already been tested in several tissues. However, no studies have applied ONT to polar bodies, a cellular material that is less restrictively regulated for PGT-A in some countries. We performed rapid short nanopore sequencing on pooled first and second polar bodies of 102 oocytes from women undergoing IVF treatment to screen for aneuploidy. An automated analysis pipeline was developed with the expectation of three chromatids per chromosome. The results were compared to those obtained by array-based comparative genomic hybridisation (aCGH). ONT and aCGH were consistent for 96% (98/102) of sample ploidy classification. Of those samples, 36 were classified as euploid, while 62 were classified as aneuploid. The four discordant samples were assessed as euploid using aCGH but classified as aneuploid using ONT. The concordance of the ploidy classification (euploid, gain, or loss) per chromosome was 92.5% (2169 of 2346 of analysed chromosomes) using aCGH and ONT and increased to 97.7% (2113/2162) without the eight samples assessed as highly complex aneuploid using ONT. The automated detection of the ploidy classification per chromosome and shorter duplications or deletions depending on the sequencing depth demonstrates an advantage of the ONT method over standard, commercial aCGH methods, which do not consider the presence of three chromatids in pooled polar bodies.

Preimplantation genetic testing for aneuploidy could not improve cumulative live birth rate among 1003 couples with recurrent pregnancy loss.

Preimplantation genetic testing for aneuploidy could not improve cumulative live birth rate among 1003 couples with recurrent pregnancy loss.

Excessive Exogenous Gonadotropins and Genetic and Pregnancy Outcomes After Euploidy Embryo Transfer

The safety of exogenous gonadotropin treatment, based on its effect on embryos and pregnancy outcomes, remains inconclusive. To evaluate the associations of different doses and durations of gonadotropins with embryonic genetic status and pregnancy outcomes after euploid embryo transfer in couples with infertility. This study was a post hoc analysis of a multicenter randomized clinical trial (RCT) conducted at 14 reproductive centers throughout China from July 2017 to June 2018 that evaluated the cumulative live birth rate with or without preimplantation genetic testing for aneuploidy (PGT-A) among couples with infertility and good prognosis. The PGT-A group from the original RCT was selected for secondary analysis. Patients were divided into 4 groups according to the total dosage of exogenous gonadotropins and treatment duration: group 1 (≤1500 IU and <10 days), group 2 (≤1500 IU and ≥10 days), group 3 (>1500 IU and <10 days), and group 4 (>1 500 IU and ≥10 days). Group 1 served as the control group. Data were analyzed from June through August 2023. Blastocyst biopsy and PGT-A. The primary outcomes were embryonic aneuploidy, embryonic mosaicism, and cumulative live birth rates after euploid embryo transfer. A total of 603 couples (mean [SD] age of prospective mothers, 29.13 [3.61] years) who underwent PGT-A were included, and 1809 embryos were screened using next-generation sequencing. The embryo mosaicism rate was significantly higher in groups 2 (44 of 339 embryos [13.0%]; adjusted odds ratio [aOR], 1.69 [95% CI, 1.09-2.64]), 3 (27 of 186 embryos [14.5%]; aOR, 1.98 [95% CI, 1.15-3.40]), and 4 (82 of 651 embryos [12.6%]; aOR, 1.60 [95% CI, 1.07-2.38]) than in group 1 (56 of 633 embryos [8.8%]). There were no associations between gonadotropin dosage or duration and the embryo aneuploidy rate. The cumulative live birth rate was significantly lower in groups 2 (83 of 113 couples [73.5%]; aOR, 0.49 [95% CI, 0.27-0.88]), 3 (42 of 62 couples [67.7%]; aOR, 0.41 [95% CI, 0.21-0.82]), and 4 (161 of 217 couples [74.2%]; aOR, 0.53 [95% CI, 0.31-0.89]) than in group 1 (180 of 211 couples [85.3%]). In this study, excessive exogenous gonadotropin administration was associated with increased embryonic mosaicism and decreased cumulative live birth rate after euploid embryo transfer in couples with a good prognosis. These findings suggest that consideration should be given to minimizing exogenous gonadotropin dosage and limiting treatment duration to improve embryo outcomes and increase the live birth rate. ClinicalTrials.gov Identifier: NCT03118141.

Assessing the necessity of screening ≤ 5 Mb segmental aneuploidy in routine preimplantation genetic testing for aneuploidy

Research QuestionDoes routine clinical practice require an increase in the resolution of preimplantation genetic testing for aneuploidy (PGT-A) to detect segmental aneuploidies (SAs) ≤ 5 Mb? DesignThis retrospective study analyzed 963 trophectoderm (TE) biopsies from 346 couples undergoing PGT between 2019 and 2023. SAs ≥ 1 Mb were reported. Characteristics, clinical interpretation and concordance of ≤ 5 Mb SAs were analyzed. ResultsThe incidence of SAs was 15.1% (145/963) in blastocysts, with SAs of 5 Mb or smaller accounting for 2.3% (22/963). The size of SAs showed a skew distribution. For SAs ≤ 5 Mb, they were found to occur more frequently on the q arm of the chromosome, compared to the p arm. Losses of ≤ 5 Mb SAs were more prevalent than gains, with 17 deletions compared to 5 duplications, respectively. 63.6% (14/22) ≤ 5 Mb SAs were of de novo and 50.0% (7/14) de novo SAs were pathogenic/likely pathogenic (P/LP) CNVs, accounting for 0.7% of 963 blastocysts. For these blastocysts carrying ≤ 5 Mb SAs, reanalysis of backup biopsy samples showed that 35.7% of de novo SAs (5/14) were not detected in the backup samples. Cases were reported that prenatal diagnosis (amniocentesis) revealed the absence of the embryonic ≤ 5 Mb SA detected at blastocyst stage. ConclusionsThe incidence of P/LP de novo ≤ 5 Mb SAs in human blastocysts is extremely low. There is no compelling need to increase the resolution of PGT-A to 5 Mb in routine clinical practice.

Natural proliferative phase frozen embryo transfer-a new approach which may facilitate scheduling without hindering pregnancy outcomes.

How does a natural proliferative phase (NPP) strategy for frozen embryo transfer (FET) compare with the conventional artificial (AC) and natural (NC) endometrial preparation protocols in terms of live birth rates (LBR)? This study supports the hypothesis that, just as for NC, NPP-FET may be a superior alternative to AC in terms of LBR. Although FETs are increasing worldwide, the optimal FET protocol is still largely controversial. Despite recent evidence supporting a possibly higher efficacy and safety of NC FETs, their widespread use is limited by the difficulties encountered during cycle monitoring and scheduling. In this single center retrospective cohort study, we describe the NPP-FET protocol, in which vaginal progesterone is initiated during the proliferative phase as soon as an endometrium with a thickness of at least 7 mm is identified and ovulation is ruled out, regardless of mean diameter of the dominant follicle. For comparison, we considered all blastocyst stage FET cycles preformed at a private infertility center between January 2010 and June 2022, subdivided according to the following subgroups of endometrial preparation: AC, NPP, and NC. We performed multivariable generalized estimating equations regression analysis to account for the following potential confounding variables: oocyte age at retrieval, oocyte source (autologous without preimplantation genetic testing for aneuploidies (PGT-A) versus autologous with PGT-A versus donated), number of oocytes retrieved/donated, embryo developmental stage (Day 5 versus Day 6), number of embryos transferred, quality of the best embryo transferred, and year of treatment. The main outcome measure was LBR. The secondary outcomes included hCG positive, clinical pregnancy and miscarriage rates, and the following perinatal outcomes: first trimester bleeding, second/third trimester bleeding, preterm rupture of membranes, gestational diabetes, gestational hypertensive disorders (GHD), and gestational age at delivery. A total of 5791 FET cycles were included in this analysis (2226 AC, 349 NPP, and 3216 NC). The LBR for FET was lower in the AC subgroup when compared to the NPP and NC (38.4%, 49.1%, and 45.2%, respectively; P < 0.01 AC versus NPP and AC versus NC). The rates of miscarriage were also lower in the NPP and NC subgroups when compared to AC (19.7%, 25.0%, and 34.9%, respectively; P < 0.01 NPP versus AC and NC versus AC). Considering perinatal outcomes, NPP-FET and NC were associated with a significantly lower first trimester bleeding compared to AC (17.3%, 14.7%, and 37.6%, respectively; P < 0.01 NPP versus AC and NC versus AC). Additionally, NC was associated with a lower rate of GHD when compared with AC (8.6% versus 14.5%, P < 0.01), while the rate following NPP-FET was 9.4%. This study is limited by its retrospective design. Moreover, there was also a low number of patients in the NPP subgroup, which may have led the study to be underpowered to detect clinically relevant differences between the subgroups. Our study posits that the NPP-FET protocol may be an effective and safe alternative to both NC and AC, while still allowing for enhanced practicality in patient follow-up and FET scheduling. Further investigation on NPP-FET is warranted, with prospective studies including a larger and more homogeneous subsets of patients. This research was supported by the IVI-RMA-Lisbon (2008-LIS-053-CG). The authors did not receive any funding for this study. The authors have no competing interests. Not applicable.

Outcomes of female reproductive performance with assisted reproductive techniques after recent mild to moderate COVID-19 infections: An observational study.

The purpose of this study was to evaluate the impact of preimplantation genetic testing for aneuploidy (PGT-A) on clinical outcomes among high-risk patients. This retrospective study involved 1,368 patients and the same number of cycles, including 520 cycles with PGT-A and 848 cycles without PGT-A. The study participants comprised women of advanced maternal age (AMA) and those affected by recurrent implantation failure (RIF), recurrent pregnancy loss (RPL), or severe male factor infertility (SMF). PGT-A was associated with significant improvements in the implantation rate (IR) and the ongoing pregnancy rate/live birth rate (OPR/LBR) per embryo transfer cycle in the AMA (39.3% vs. 16.2% [p<0.001] and 42.0% vs. 21.8% [p<0.001], respectively), RIF (41.7% vs. 22.0% [p<0.001] and 47.0% vs. 28.6% [p<0.001], respectively), and RPL (45.6% vs. 19.5% [p<0.001] and 49.1% vs. 24.2% [p<0.001], respectively) groups, as well as the IR in the SMF group (43.3% vs. 26.5%, p=0.011). Additionally, PGT-A was associated with lower overall incidence rates of pregnancy loss in the AMA (16.7% vs. 34.3%, p=0.001) and RPL (16.7% vs. 50.0%, p<0.001) groups. However, the OPR/LBR per total cycle across all PGT-A groups did not significantly exceed that for the control groups. PGT-A demonstrated beneficial effects in high-risk patients. However, our findings indicate that these benefits are more pronounced in carefully selected candidates than in the entire high-risk patient population.

Detection of Germline Mosaicism for Robertsonian Translocation 14;14: A Case Report

Background: Chromosomal structural rearrangements can lead to fertility problems and recurrent miscarriages. The intricate interplay of genetics during human development can lead to subtle anomalies that may affect reproduction.&#x0D; Case Presentation: A 33-year-old woman sought fertility treatment after experiencing six miscarriages. Products of conception from the final pregnancy loss had been karyotyped, revealing a Robertsonian translocation (RT), involving chromosome 14. Fertility investigations showed low anti-Mullerian hormone (AMH) levels but otherwise normal female characteristics with normal sperm parameters of her husband were observed and both partners having a normal karyotype. Two embryos were transferred in an IVF cycle but neither resulted in a successful pregnancy. Subsequently, preimplantation genetic testing for aneuploidy (PGT-A) was applied to trophectoderm biopsy specimens from 4 embryos, which revealed abnormalities involving chromosome 14. Sperm aneuploidy testing failed to detect any increase in the incidence of aneuploidy affecting chromosome 14. Further embryos genetic testing indicated that all identified chromosome 14 abnormalities in the embryos had a maternal (oocyte) origin.&#x0D; Conclusion: This case underscores challenges in diagnosing and managing germline mosaicism in fertility. A maternal 14;14 Robertsonian translocation, undetected in the patient's blood but impacting oocytes, likely explains recurrent miscarriage and observed embryo aneuploidies. Genetic mosaicism in reproductive medicine highlights the necessity for advanced testing and personalized treatments. Data integration from various genetic analyses could enhance managing treatment expectations and improving fertility experiences.

Evaluation of Nanopore Sequencing on Polar Bodies for Routine Pre-Implantation Genetic Testing for Aneuploidy.

Preimplantation genetic testing for aneuploidy (PGT-A) using polar body (PB) biopsy offers a clinical benefit by reducing the number of embryo transfers and miscarriage rates but is currently not cost-efficient. Nanopore sequencing technology opens possibilities by providing cost-efficient and fast sequencing results with uncomplicated sample preparation work flows. In this comparative experimental study, 102 pooled PB samples (99 passing QC) from 20 patients were analyzed for aneuploidy using nanopore sequencing technology and compared with array comparative genomic hybridization (aCGH) results generated as part of the clinical routine. Samples were sequenced on a Nanopore MinION machine. Whole-chromosome copy-numbers were called by custom bioinformatic analysis software. Automatically called results were compared to aCGH results. Overall, 96/99 samples were consistently detected as euploid or aneuploid in both methods (concordance = 97.0%, sensitivity = 0.957, specificity = 1.0, positive predictive value = 1.0, negative predictive value = 0.906). On the chromosomal level, concordance reached 98.7%. Chromosomal aneuploidies analyzed in this trial covered all 23 chromosomes with 98 trisomies, and 97 monosomies in 70 aCGH samples.The whole nanopore work flow is feasible in under 5 h (for one sample) with a maximum time of 16 h (for 12 samples), enabling fresh PB-euploid embryo transfer. A material cost of US$ 165 (EUR 150)/sample possibly enables cost-efficient aneuploidy screening. This is the first study systematically comparing nanopore sequencing with standard methods for the detection of PB aneuploidy. High concordance rates confirmed the feasibility of nanopore technology for this application. Additionally, the fast and cost-efficient work flow reveals the clinical utility of this technology, making it clinically attractive for PB PGT-A.

Extracellular vesicles secreted by human aneuploid embryos present a distinct transcriptomic profile and upregulate MUC1 transcription in decidualised endometrial stromal cells.

Do extracellular vesicles (EVs) secreted by aneuploid human embryos possess a unique transcriptomic profile that elicits a relevant transcriptomic response in decidualized primary endometrial stromal cells (dESCs)? Aneuploid embryo-derived EVs contain transcripts of PPM1J, LINC00561, ANKRD34C, and TMED10 with differential abundance from euploid embryo-derived EVs and induce upregulation of MUC1 transcript in dESCs. We have previously reported that IVF embryos secrete EVs that can be internalized by ESCs, conceptualizing that successful implantation to the endometrium is facilitated by EVs. Whether these EVs may additionally serve as biomarkers of ploidy status is unknown. Embryos destined for biopsy for preimplantation genetic testing for aneuploidy (PGT-A) were grown under standard conditions. Spent media (30 μl) were collected from euploid (n = 175) and aneuploid (n = 140) embryos at cleavage (Days 1-3) stage and from euploid (n = 187) and aneuploid (n = 142) embryos at blastocyst (Days 3-5) stage. Media samples from n = 35 cleavage-stage embryos were pooled in order to obtain five euploid and four aneuploid pools. Similarly, media samples from blastocysts were pooled to create one euploid and one aneuploid pool. ESCs were obtained from five women undergoing diagnostic laparoscopy. EVs were isolated from pools of media by differential centrifugation and EV-RNA sequencing was performed following a single-cell approach that circumvents RNA extraction. ESCs were decidualized (estradiol: 10 nM, progesterone: 1 µM, cAMP: 0.5 mM twice every 48 h) and incubated for 24 h with EVs (50 ng/ml). RNA sequencing was performed on ESCs. Aneuploid cleavage stage embryos secreted EVs that were less abundant in RNA fragments originating from the genes PPM1J (log2fc = -5.13, P = 0.011), LINC00561 (log2fc = -7.87, P = 0.010), and ANKRD34C (log2fc = -7.30, P = 0.017) and more abundant in TMED10 (log2fc = 1.63, P = 0.025) compared to EVs of euploid embryos. Decidualization per se induced downregulation of MUC1 (log2fc = -0.54, P = 0.0028) in ESCs as a prerequisite for the establishment of receptive endometrium. The expression of MUC1 transcript in decidualized ESCs was significantly increased following treatment with aneuploid compared to euploid embryo-secreted EVs (log2fc = 0.85, P = 0.0201). Raw data have been uploaded to GEO (accession number GSE234338). The findings of the study will require validation utilizing a second cohort of EV samples. The discovery that the transcriptomic profile of EVs secreted from aneuploid cleavage stage embryos differs from that of euploid embryos supports the possibility to develop a non-invasive methodology for PGT-A. The upregulation of MUC1 in dESCs following aneuploid embryo EV treatment proposes a new mechanism underlying implantation failure. The study was supported by a Marie Skłodowska-Curie Actions fellowship awarded to SM by the European Commission (CERVINO grant agreement ID: 79620) and by a BIRTH research grant from Theramex HQ UK Ltd. The authors have no conflicts of interest to declare.

Economic evaluations of assisted reproductive technologies in high-income countries: a systematic review.

Which assited reproductive technology (ART) interventions in high-income countries are cost-effective and which are not? Among all ART interventions assessed in economic evaluations, most high-cost interventions, including preimplantation genetic testing for aneuploidy (PGT-A) for a general population and ICSI for unexplained infertility, are unlikely to be cost-effective owing to minimal or no increase in effectiveness. Approaches to reduce costs in order to increase access have been identified as a research priority for future infertility research. There has been an increasing number of ART interventions implemented in routine clinical practice globally, before robust assessments of evidence on economic evaluations. The extent of clinical effectiveness of some studied comparisons has been evaluated in high-quality research, allowing more informative decision making around cost-effectiveness. We performed a systematic review and searched seven databases (MEDLINE, PUBMED, EMBASE, COCHRANE, ECONLIT, SCOPUS, and CINAHL) for studies examining ART interventions for infertility together with an economic evaluation component (cost-effectiveness, cost-benefit, cost-utility, or cost-minimization assessment), in high-income countries, published since January 2011. The last search was 22 June 2022. Two independent reviewers assessed publications and included those fulfilling the eligibility criteria. Studies were examined to assess the cost-effectiveness of the studied intervention, as well as the reporting quality of the study. The chosen outcome measure and payer perspective were also noted. Completeness of reporting was assessed against the Consolidated Health Economic Evaluation Reporting Standard. Results are presented and summarized based on the intervention studied. The review included 40 studies which were conducted in 11 high-income countries. Most studies (n = 34) included a cost-effectiveness analysis. ART interventions included medication or strategies for controlled ovarian stimulation (n = 15), IVF (n = 9), PGT-A (n = 7), single embryo transfer (n = 5), ICSI (n = 3), and freeze-all embryo transfer (n = 1). Live birth was the mostly commonly reported primary outcome (n = 27), and quality-adjusted life years was reported in three studies. The health funder perspective was used in 85% (n = 34) of studies. None of the included studies measured patient preference for treatment. It remains uncertain whether PGT-A improves pregnancy rates compared to IVF cycles managed without PGT-A, and therefore cost-effectiveness could not be demonstrated for this intervention. Similarly, ICSI in non-male factor infertility appears not to be clinically effective compared to standard fertilization in an IVF cycle and is therefore not cost-effective. Interventions such as use of biosimilars or HMG for ovarian stimulation are cheaper but compromise clinical effectiveness. Lack of both preference-based and standardized outcomes limits the comparability of results across studies. The selection of efficacy evidence offered for some interventions for economic evaluations is not always based on high-quality randomized trials and systematic reviews. In addition, there is insufficient knowledge of the willingness to pay thresholds of individuals and state funders for treatment of infertility. There is variable quality of reporting scores, which might increase uncertainty around the cost-effectiveness results. Investment in strategies to help infertile people who utilize ART is justifiable at both personal and population levels. This systematic review may assist ART funders decide how to best invest to maximize the likelihood of delivery of a healthy child. There was no funding for this study. E.C. and R.W. receive salary support from the National Health and Medical Research Council (NHMRC) through their fellowship scheme (EC GNT1159536, RW 2021/GNT2009767). M.D.-T. reports consulting fees from King Fahad Medical School. All other authors have no competing interests to declare. Prospero CRD42021261537.

Aneuploidy in Oocytes From Women of Advanced Maternal Age: Analysis of the Causal Meiotic Errors and Impact on Embryo Development

ABSTRACT Many chromosome abnormalities are commonly observed and can lead to early pregnancy loss, miscarriage, or the birth of children with chromosomal defects. Such abnormalities are considered a major factor in the low pregnancy rate after assisted reproductive technology and natural conception. Preimplantation genetic testing for aneuploidy (PGT-A) aims to minimize the transfer of aneuploid embryos. Embryonic aneuploidies arising from errors in meiosis have an incidence of approximately 25% in embryos from women younger than 35 years, to more than half in embryos from women aged older than 35 years. Although these embryos are able to develop to the blastocyst stage, they tend to be of lower morphological quality. A recent multicenter randomized clinical trial (ESTEEM) analyzed polar bodies (PBs) from women after intracytoplasmic sperm injection aged between 36 and 40 years using microarrays in 205 cycles and found that the transfer of embryos from euploid oocytes did not lead to a higher live birth rate but was associated with a reduction in the number of embryo transfers and miscarriages. This study aimed to evaluate all PB results from this RCT and characterize the types of chromosomal abnormalities and the chromosomes most frequently affected. The ESTEEM trial obtained biopsy of first (PB1) and second (PB2) PB in the cohort receiving PGT-A and analyzed them using array comparative genomic hybridization (aCGH). A total of 693 PB pairs had full results available, including 676 confirmed fertilized oocytes. Chromosome segregations, including likely underlying mechanisms, from these pairs are reported here. To estimate the reliability of the aCGH procedure, 72 PB pairs from a single center were reanalyzed using next-generation sequencing (NGS). Embryos were classified into 4 categories based on morphology: good, fair, poor, and degenerated. A comparative analysis was performed to assess the association between chromosome status and embryo quality as well as study group (PGT-A vs control) and embryo quality. A total of 213/676 oocytes were euploid and 413/676 were aneuploid, whereas in the remaining 50 oocytes, an abnormality observed in PB1 was compensated by an abnormality in PB2. A total of 693 PB pairs reported chromatic numbers with results for 15,939 chromosomes. An abnormal segregation, in PB1 and/or PB2, was observed in 1162 chromosomes (7.3%) in 461 PB pairs. Chromosomes 22 (16.7%), 16 (16.6%), 19 (14.4%), 21 (13.7%), and 15 (12.4%) had the highest frequencies for abnormal segregations. The abnormal segregations were compatible with precocious separation of sister chromatids in meiosis 1 (M1) (n = 568; 48.9%), nondisjunction of chromatics in meiosis 2 (M2) or reverse segregation (n = 417; 35.9%), and nondisjunction in M1 (n = 65; 5.6%). However, 112 chromosomes had segregation patterns that could not be categorized into 1 of the 9 known mechanisms causing aneuploidy in oocytes. Concordance between aCGH and NGS was obtained for both PBs for 1650 of 1656 analyzed chromosomes (99.6%). Embryos predicted to be aneuploid had significantly worse quality scores on day 3 (adjusted odds ratio [aOR], 0.62; 95% confidence interval [CI], 0.43–0.90), day 4 (aOR, 0.15; 95% CI, 0.06–0.39), and day 5 (aOR, 0.28; 95% CI, 0.14–0.58). This study represents one of the largest analyses of chromosomal copy number in both PBs to date and highlights the frequent unexplained chromosome copy numbers underscoring the gap of knowledge into the mechanisms causing aneuploidy in oocytes.