Faculty Bibliography

OBJECTIVE: To compare the rates of euploid embryos in FRESH vs. OOT cycles. DESIGN: Retrospective cohort study of all FRESH vs. OOT cycles, including donors, undergoing preimplantation genetic screening (PGS) with microarray-based comparative genomic hybridization (aCGH) or next-generation sequencing (NGS) from 2011-2015 at a single, high-volume university-based fertility center. MATERIALS AND METHODS: Embryos biopsied for PGS derived from FRESH were compared to those from OOTon a per-cycle basis (n=1643 and 111, respectively). PGS was performed by aCGH or NGS for both FRESH (n=1149 and 504, respectively) and OOT (n=64 and 47, respectively). Age was controlled for by linear regression analysis of euploidy rate vs age. Euploid embryos were divided into no. euploid per egg and no. euploid per embryo biopsied and by method of PGS performed; comparison was made by examining residuals from the regression line for FRESH. SEM and t test were used. RESULTS: The average no. of euploid blasts per FRESH cycle was 1.77+/-2.26 and 1.19+/-1.61 for aCGH and NGS respectively; the average no. of eggs was 13.8+/-8.0 and 13.8+/-8.4. The average no. of euploid blasts per OOT cycle was 1.24+/-1.65 and 0.85+/-1.01 for aCGH and NGS respectively; the average no. of eggs per thaw was 14.72+/-8.8 and 13.69+/-5.71. Euploidy rate per egg was significantly lower in the OOT than in the FRESH for both aCGH and NGS when analyzing the mean residuals from the regression line. However, there was no difference in euploidy rate per biopsied blast in either group, irrespective of PGS method. CONCLUSIONS: Previous research at our facility has shown that the blast formation rate is significantly lower in OOT vs FRESH [1]. After controlling for the age-effect on aneuploidy, we observed that the euploidy rate per egg was lower in the OOT vs the FRESH for both aCGH and NGS; this difference disappears once the embryos make it to blastocyst stage, as there was no difference in no. of euploid per embryos biopsied. The difference in average no. eggs in FRESH vs OOT is insignificant and a misleading comparison as all oocytes retrieved were not thawed in totality for each OOT. The data suggest that attrition in the OOT group may be secondary to the cryopreservation technique, although attrition occurs regardless of ploidy. Further improvements in cryopreservation technique are necessary to optimize patient outcomes

OBJECTIVE: To compare early embryo development rates in fresh IVF (FRESH) vs previously-cryopreserved oocyte thaw (OOT) cycles. DESIGN: Retrospective cohort study including all FRESH and OOT from 2005-2015 at a single, high-volume university-based fertility center. MATERIALS AND METHODS: Embryos derived from FRESH (n=95,260) were compared to those from OOT (n=1,730) on a per-embryo basis. Primary outcome measures included number of cells present on embryonic day (D) 2 and D3, overall blast formation rate (BFR) and BFR achieved on D5. Chi-square was used for analysis. RESULTS: The table shows early embryo development of FRESH vs. OOT embryos. 2PN fertilization rates were clinically comparable. On D2 and D3, the mean no. of cells and % of embryos reaching 4 and 8 cells were significantly lower for OOT compared to FRESH. Additionally, overall BFR was lower in OOT (48.3%) vs. FRESH (60.8%), although both groups had a near 50% BFR by D5 (46.7% and 48.4%, respectively). CONCLUSIONS: Previous research at our facility has shown no difference in live birth rate per mature oocyte retrieved or per embryo transferred when comparing OOTand FRESH; however, a lower BFR was demonstrated [1]. Here, we confirm the latter and pinpoint the developmental perturbation to an earlier embryonic stage, signifying a maternal genome signaling insult. Although little research has been performed in the OOT population, mouse studies on standard frozen embryos suggest human genes may be linked to embryonic growth control [2]. Other animal studies show that cryprotectants may impact chromosomal function or cause osmotic damage to oocytes [3-5]. Reassuringly, D5 BFR was not different when comparing FRESH and OOT; this signifies developmental competence even after freezing and bolsters freezing as a valuable means of fertility preservation. We are currently working to elucidate what exactly this disruption may be through time-lapse imaging and embryo transcriptome analysis

OBJECTIVE: To further understanding of how women who pursue OC for deferred reproduction think and act relative to reproduction and dating. DESIGN: 2016 anonymous 39-question survey with comparison to our prior OC patient survey completed in 2012. MATERIALS AND METHODS: From 2005-15, 1817 women underwent >1 OC treatment cycle at our facility; 866 (48%) agreed to post-treatment contact, and our survey was distributed to these patients. RESULTS: There were 224 survey responses (rate: 26%). From 2012 to 2016, the percentage of women that froze at 33-35y increased (13 to 24%) while those 39-41y decreased (39 to 23%); 44% froze between 36-38y consistent with our clinical data also demonstrating a decrease in age at time of OC. 53% underwent OC in the last 2 years. As in 2012, 80% of respondents were Caucasian, and >70% were never married, reported lack of partner as the no. 1 reason for not yet having children and wished they had undergone OC earlier. The majority now feel the ideal age for egg freezing is 29-34y, with only 16% choosing >35y and <1% choosing >38y. Of note, more (25 vs. 16%) were in a relationship at time of OC with 1/2stating the relationship was <1y. 77% reported difficulty finding someone with whom to co-parent at the time of OC. >80% currently report a desire to have children while <20% remain unsure as to whether they definitely want children in the future. Cost was the greatest obstacle to pursuing OC. 1/3 received financial support, mostly from family, with parents being the most common source. After OC, 30% admitted an attitude change toward parenting, mostly in a positive way (i.e. made it a priority or increased openness to alternative family-creating options). >60% also felt lessening of biological-clock pressure when dating and were more open to using donor sperm if still lacking a suitable partner by age 43 (average; range 35-50y). 1/4 said OC changed their dating habits: feeling more relaxed, focused, less desperate and with more time to find the right partner. >60% admitted discussing OC while dating and 90% with family/friends. They were most often met with positive/ supportive reception. 96% would recommend OC to another. After undergoing OC, 22% got pregnant or had children without resorting to their frozen eggs (2/3 naturally; 1/3 ART; 4% adoption). 13% of respondents thawed eggs resulting in a 32% live birth rate. Of those not yet thawing, 1/2 cited lacking a suitable co-parent as the obstacle; 90% reported future intent to thaw. CONCLUSIONS: Women are pursuing OC at younger ages, with the primary indication being lack of a suitable co-parenting partner; the latter was also the most common reason cited for not returning to use eggs sooner. Cost was prohibitive for many, with some relying on family finances. Most reported OC as a positive experience, improving views of parenting, inciting healthier dating practices, enhancing hope for future family and expanding acceptable options for achieving that goal

OBJECTIVE: To demonstrate that oocyte cryopreservation is a feasible reproductive option for patients with cancer of childbearing age who require gonadotoxic therapies. METHODS: This study is a university-based retrospective review of reproductive-aged cancer patient treatment cycles that included ovarian stimulation, transvaginal oocyte retrieval, oocyte cryopreservation, and, in some cases, subsequent oocyte thaw, in vitro fertilization, and embryo transfer. Outcome measures included ovarian stimulation response, number of oocytes retrieved, cryopreserved, and thawed, and pregnancy data. RESULTS: From 2005 to 2014, 176 reproductive-aged patients with cancer (median age 31 years, interquartile range 24-36) completed 182 oocyte cryopreservation cycles. Median time between consult request and oocyte retrieval was 12 days (interquartile range 10-14). Median peak stimulation estradiol was 1,446 pg/mL (interquartile range 730-2,687); 15 (interquartile range 9-23) oocytes were retrieved and 10 (interquartile range 5-18) metaphase II oocytes were cryopreserved per cycle. Ten patients (11 cycles) have returned to attempt pregnancy with their cryopreserved oocytes. Among thawed oocytes, the cryopreservation survival rate was 86% (confidence interval [CI] 78-94%). Nine of 11 thaw cycles resulted in embryos suitable for transfer. The embryo implantation rate was 27% (CI 8-46%) and the live birth rate was 44% (CI 12-77%) per embryo transfer. Chance for live birth with embryos created from cryopreserved oocytes was similar between the patients with cancer in this study and noncancer patients who underwent the same treatment at our center (44% [CI 12-77%] compared with 33% [CI 22-44%] per embryo transfer). CONCLUSION: Oocyte cryopreservation is now a feasible fertility preservation option for reproductive-aged patients with cancer who require gonadotoxic therapies.

BACKGROUND: In vitro fertilization (IVF) data suggest improved live birth rates for embryos transferred at the blastocyst versus the cleavage stage. Embryos that have not reached the blastocyst stage by day 5 postthaw have diminished potential for implantation and live birth. Few data exist regarding embryogenesis and optimal timing of transfer for embryos derived from previously cryopreserved oocytes, but we report the case of 100% implantation following transfer of 3 developmentally-delayed embryos derived from cryopreserved oocytes. CASE: A 38-year-old woman cryopreserved 20 oocytes for the purpose of future childbearing. At age 42 she returned to thaw and fertilize 8 oocytes using donor sperm. Embryos were cultured to day 5 postthaw, at which time 1 morula and 2 cleavage-stage embryos were available for transfer. Three-embryo transfer resulted in a heterotopic tubal pregnancy and twin intrauterine gestation. Laparoscopic salpingectomy was performed for the ectopic gestation. The twin intrauterine pregnancy spontaneously reduced to singleton, and the patient delivered a live-born infant. CONCLUSION: While heterotopic and multifetal pregnancy are known risks of multiembryo transfer, 3 lesser-quality embryos derived from cryopreserved oocytes would be unlikely to have high implantation potential. Future studies are needed to delineate timing of embryogenesis events in previously cryopreserved oocytes.

OBJECTIVE: To determine whether oocyte cryopreservation for deferred reproduction is cost effective per live birth using a model constructed from observed clinical practice. DESIGN: Decision-tree mathematical model with sensitivity analyses. SETTING: Not applicable. PATIENT(S): A simulated cohort of women wishing to delay childbearing until age 40 years. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Cost per live birth. RESULT(S): Our primary model predicted that oocyte cryopreservation at age 35 years by women planning to defer pregnancy attempts until age 40 years would decrease cost per live birth from $55,060 to $39,946 (and increase the odds of live birth from 42% to 62% by the end of the model), indicating that oocyte cryopreservation is a cost-effective strategy relative to forgoing it. If fresh autologous assisted reproductive technology (ART) was added at age 40 years, before thawing oocytes, 74% obtained a live birth, and cost per live birth increased to $61,887. Separate sensitivity analyses demonstrated that oocyte cryopreservation remained cost effective as long as performed before age 38 years, and more than 49% of those women not obtaining a spontaneously conceived live birth returned to thaw oocytes. CONCLUSION(S): In women who plan to delay childbearing until age 40 years, oocyte cryopreservation before 38 years of age reduces the cost to obtain a live birth.

OBJECTIVE: To determine if long-term cryopreservation of human oocytes affects oocyte developmental competence, blastocyst euploidy, or live-birth rates. DESIGN: Retrospective cohort study. SETTING: University-based fertility center. PATIENT(S): A total of 33 patients with cryopreserved oocytes underwent oocyte thaw, blastocyst culture, trophectoderm biopsy, and 24-chromosome preimplantation genetic screening (PGS) with array comparative genomic hybridization between December 2011 and July 2014; subjects were compared with 2:1 age-matched controls with fresh oocytes whose embryos underwent trophectoderm biopsy and PGS during the same period. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Rates of fertilization, blastulation, euploidy, implantation, and live birth. RESULT(S): Thirty-three patients (mean age 36.2 +/- 3.8 y) thawed 475 oocytes that had been cryopreserved for a median of 3.5 years. Compared with 66 age-matched controls who underwent in vitro fertilization and PGS with fresh oocytes, embryos derived from cryopreserved oocytes demonstrated compromised blastocyst formation (54.5% vs. 66.2%) despite no impairment in fertilization (72.8% vs. 73.2%). Results showed no difference in the number of euploid blastocysts (1.7 +/- 1.9 vs. 2 +/- 2.5), percentage of euploid blastocysts (44.5% vs. 47.6%), rate of implantation (65% vs. 65%), or rate of live birth and ongoing pregnancy (62.5% vs. 55%) after 24-chromosome PGS with cryopreserved or fresh oocytes. CONCLUSION(S): Embryos derived from cryopreserved oocytes demonstrate impaired blastulation but equivalent rates of euploidy, implantation, and live birth compared with blastocysts derived from fresh oocytes, supporting the safety and efficacy of oocyte cryopreservation.