Faculty Bibliography

The objective of this review is to provide an update on planned oocyte cryopreservation. This fertility preservation method increases reproductive autonomy by allowing women to postpone childbearing whilst maintaining the option of having a biological child. Oocyte cryopreservation is no longer considered experimental, and its use has increased dramatically in recent years as more women delay childbearing for personal, professional and financial reasons. Despite increased usage, most patients who have undergone oocyte cryopreservation have not yet warmed their oocytes. Most women who cryopreserve oocytes wait years to use them, and many never use them. Studies have demonstrated that oocyte cryopreservation results in live birth rates comparable with IVF treatment using fresh oocytes, and does not pose additional safety risks to offspring. Based on current evidence, cryopreserving ≥20 mature oocytes at <38 years of age provides a 70% chance of one live birth. However, larger studies from a variety of geographic locations and centre types are needed to confirm these findings. Additional research is also needed to determine the recommended age for oocyte cryopreservation, recommended number of oocytes to cryopreserve, return and discard/non-use rates, cost-effectiveness, and how best to distribute accurate and up-to-date information to potential patients.

OBJECTIVE:To review the outcomes of patients who underwent autologous oocyte thaw after planned oocyte cryopreservation. DESIGN/METHODS:Retrospective cohort study. SETTING/METHODS:Large urban university-affiliated fertility center. PATIENT(S)/METHODS:All patients who underwent ≥1 autologous oocyte thaw before December 31, 2020. INTERVENTION(S)/METHODS:None. MAIN OUTCOME MEASURE(S)/METHODS:The primary outcome was the final live birth rate (FLBR) per patient, and only patients who had a live birth (LB) or consumed all remaining inventory (cryopreserved oocytes and resultant euploid/untested/no result embryos) were included. The secondary outcomes were laboratory outcomes and LB rates per transfer. RESULT(S)/RESULTS:A total of 543 patients underwent 800 oocyte cryopreservations, 605 thaws, and 436 transfers. The median age at the first cryopreservation was 38.3 years. The median time between the first cryopreservation and thaw was 4.2 years. The median numbers of oocytes and metaphase II oocytes (M2s) thawed per patient were 14 and 12, respectively. Overall survival of all thawed oocytes was 79%. Of all patients, 61% underwent ≥1 transfer. Among euploid (n = 262) and nonbiopsied (n = 158) transfers, the LB rates per transfer were 55% and 31%, respectively. The FLBR per patient was 39%. Age at cryopreservation and the number of M2s thawed were predictive of LB; the FLBR per patient was >50% for patients aged <38 years at cryopreservation or who thawed ≥20 M2s. A total of 173 patients (32%) have remaining inventory. CONCLUSION(S)/CONCLUSIONS:Autologous oocyte thaw resulted in a 39% FLBR per patient, which is comparable with age-matched in vitro fertilization outcomes. Studies with larger cohorts are necessary.

OBJECTIVE: The causes of spontaneous abortion (SAB) following euploid embryo transfer (EET) remain poorly understood. Here we describe the frequency of aneuploidy in products of conception (POC) and endometrial dysfunction in women who miscarried after EET. MATERIALS AND METHODS: Between 1/2018 - 8/2020, 255 dilation and curettage (D&C) procedures were performed at a large academic IVF center for SAB following EET. Retrospective chart review was performed to identify D&Cs followed with genetic analysis of POCs. Information collected from the medical record included assessments of endometrial dysfunction based on Endometrial Receptivity Assay (ERA), CD138 for chronic endometritis (CE), and/or BCL6 for endometriosis. Exclusion criteria included an abnormal endometrial cavity on imaging. Demographic factors, clinical parameters and IVF/FET outcomes were reviewed. Additionally, retrospective chart review was performed of all ERAs completed at our institution from 12/2018-9/2020.
RESULT(S): Genetic analysis of 67 POCs after D&C following EET were identified. Fifty-nine POCs (88%) were euploid by SNP microarray. Eight (12%) of the POCs displayed genetic abnormalities: 3 trisomies, 2 partial duplications, 2 mosaic trisomies and 1 triploidy of paternal origin. Of the 51 patients who had endometrial biopsy (EMB), 28 (55%) had normal results. Twenty-three (45%) had abnormal results: 18 with CE, 2 with elevated BCL6 and 3 with pre-receptive ERA. The proportion of SABs unexplained by endometrial dysfunction or genetically abnormal POCs was 38% (26). A total of 44 patients underwent repeat EET. Eleven live births (LB) occurred, six after correction of endometrial dysfunction. Eight patients currently have ongoing pregnancy, 2 after treatment for CE. Three patients experienced repeat SAB, 1 following correction of pre-receptive ERA, and 1 after CE treatment. Four patients had implantation failure, 3 following normal EMB and 1 after treatment of CE. Two patients conceived spontaneously and delivered, 1 after treatment for CE, the other after a normal EMB. Upon review of all ERAs, 82 single EET following ERA guidance were identified. Fifty-nine percent (n=48) resulted in ongoing pregnancy or LB. There was no significant difference in ERA result or post ERA transfer outcome based on ethnicity (p= 0.7, p=0.4) or BMI (p= 0.8, 0.9), respectively. There was also no difference in post ERA transfer outcome based on blastocyst age (day 5 or 6) (p=0.5)
CONCLUSION(S): Aneuploidy and/or endometrial factor can contribute to SAB following EET. Aneuploid POCs could have arisen de novo and/or have passed undetected by trophectoderm biopsy and NGS. Our results are consistent with the 1-2% false negative rate reported for PGT-A. Further studies are needed to characterize the sub-chromosomal genetic variations associated with euploid embryo SABs, as well as endometrial function testing. IMPACT STATEMENT: The etiology behind failed EET may involve more discrete entities such as sub-chromosomal abnormalities in addition to aneuploidy and endometrial dysfunction

OBJECTIVE:To evaluate the outcomes of planned oocyte cryopreservation patients most likely to have a final disposition. DESIGN/METHODS:Retrospective cohort study of all patients who underwent at least 1 cycle of planned oocyte cryopreservation between Jan 2005 and December 2009. SETTING/METHODS:Large urban University-affiliated fertility center PATIENT(S): All patients who underwent ≥1 cycle of planned oocyte cryopreservation in the study period. INTERVENTION(S)/METHODS:None MAIN OUTCOME MEASURE(S): Primary outcome was the disposition of oocytes at 10-15 years. Secondary outcomes included thaw/warming types, laboratory outcomes, and live birth rates. Outcomes and variables treated per patient. RESULT(S)/RESULTS:A total of 231 patients with 280 cycles were included. The mean age at the first retrieval was 38.2 years (range 23-45). A total of 3,250 oocytes were retrieved, with an average of 10 metaphase II frozen/retrieval. To date, the oocytes of 88 patients (38.1%) have been thawed/warmed, 109 (47.2%) remain in storage, 27 (11.7%) have been discarded, and 7 (3.0%) have been transported elsewhere. The return rate (patients who thawed/warmed oocytes) was similar by Society for Assisted Reproductive Technology age group. The mean age of patients discarding oocytes was 47.4 years (range, 40-57). Of the 88 patients who thawed/warmed oocytes, the mean age at the time of thaw/warming was 43.9 years (range, 38-50) with a mean of 5.9 years frozen (range, 1-12). Nine patients (10.2%) thawed/warmed for secondary infertility. A total of 62.5% of patients created embryos with a partner, and 37.5% used donor sperm. On average, 14.3 oocytes were thawed/warmed per patient, with 74.2% survival (range, 0%-100%) and a mean fertilization rate of 68.8% of surviving oocytes. Of 88 patients, 39 (44.3%) planned a fresh embryo transfer (ET); 36 of 39 patients had at least 1 embryo for fresh ET, and 11 had a total of 14 infants. Forty-nine of 88 patients (55.7%) planned for preimplantation genetic testing for aneuploidy, with a mean of 4.2 embryos biopsied (range, 0-14) and a euploidy rate of 28.9%. Of the 49 patients, 17 (34.7%) had all aneuploidy or no embryos biopsied. Twenty-four patients underwent a total of 36 single euploid ET with 18 live births from 16 patients. Notably, 8 PGT-A patients had a euploid embryo but no ET, affecting the future cumulative pregnancy rate. Overall, 80 patients with thaw/warming embryos had a final outcome. Of these, 20 had nothing for ET (arrested/aneuploid), and of the 60 who had ≥1 ET, 27 had a total of 32 infants, with a live birth rate of 33.8% (27/80). CONCLUSION(S)/CONCLUSIONS:We report the final outcomes of patients most likely to have returned, which is useful for patient counseling: a utilization rate of 38.1% and a no-use rate of 58.9%, similar across age groups. Further studies with larger cohorts as well as epidemiologic comparisons to patients currently cryopreserving are needed.

Objective Improvements in oocyte cryopreservation(OC) have led to successful oocyte banking and more readily available cryopreserved donor oocytes(DO). Simultaneously, preimplantation genetic screening(PGS) has increased, even with DO. Using OC, DO, and PGS together is less common, but now occurs. Reservations include increased technological and financial cost ($1,100/oocyte). Our goal was to determine whether adding PGS increases implantation and live birth rates in DOT. Design Retrospective cohort study. Material and Methods We conducted a retrospective analysis of DOT performed 10/2004-1/2017 at a university-based fertility center. To remove bias, we conducted a sub-analysis of single embryo transfers(SET). Data was mined for: number of oocytes thawed/survived/fertilized, embryo development/transfer/implantation, and ongoing pregnancy/live birth. Mood's median and Fischer's exact tests were used for statistical analysis. Results Within the 130 non-PGS DOT (118 pts, median age:26y), 1138 oocytes (median:8/cycle) were thawed. Within the 15 PGS DOT (15 pts, median age:24y), 180 oocytes (median:11/cycle) were thawed a mean of 3 blastocysts(BL) were biopsied. Oocyte survival, 2-PN fertilization, BL formation, implantation, and ongoing pregnancy/live birth rates were not significantly different between the groups. The multiple birth rate in the non-PGS group was 6% (5/84 births). When controlling for SET, no differences were found in implantation or ongoing pregnancy/live birth rates with and without PGS (p>.1). When comparing embryo quality in the non-PGS group, a higher ongoing pregnancy/live birth rate was noted among SETs with excellent-quality Gardner's >2Bb (62% 50 births/81 transfers) when compared with SETs with poor-quality Gardner's <2Bb (35% 8 births/23 transfers p=.03). Conclusions Due to this study's small sample size, it is difficult to conclude whether PGS improves implantation/live birth rates in a young donor population. In DO cycles with excellent-quality BL for transfer, morphology alone predicts a high live birth rate. Given the financial and technological burden of PGS, larger studies are needed to determine whether the costs of PGS outweigh the benefits in DO cycles