Fresh embryo transfer after in vitro insemination of fresh vs. cryopreserved anonymous donor oocytes: which has a better live birth rate? A Society for Assisted Reproductive Technology Clinic Outcome Reporting System analysis

Abstract

Objective: To determine if transfer of fresh embryos derived from fresh or cryopreserved donor oocytes yields a higher live birth rate.

Design: Historical cohort study.

Setting: Society for Assisted Reproductive Technology Clinic Outcome Reporting System database.

Patient(s): A total of 24,663 fresh embryo transfer cycles of donor oocytes.

Intervention(s): None.

Main outcome measure(s): The primary outcome was live births per number of embryos transferred on day 5. The secondary outcomes included number of infants per embryo transfer, surplus embryos cryopreserved, and characterization of US oocyte recipients.

Result(s): A total of 16,073 embryo transfers were from fresh oocytes and 8,590 were from cryopreserved oocytes. Recipient age, body mass index (BMI), gravidity, and parity were similar between the groups. Most recipients were of White non-Hispanic race (66.9%), followed by Asian (13.7%), Black non-Hispanic (9.3%), and Hispanic (7.2%). Fresh oocyte cycles were more likely to use elective single embryo transfer (42.5% vs. 37.8%) or double embryo transfer (53.2% vs. 50.4%) and resulted in more surplus embryos for cryopreservation (4.6 vs. 1.2). The live birth rate from fresh oocytes was 57.5% vs. 49.7% from cryopreserved oocytes. Negative predictors of live birth included the use of cryopreserved oocytes (odds ratio [OR] 0.731, 95% confidence interval [CI] 0.665-0.804), Black non-Hispanic race (OR 0.603, 95% CI 0.517-0.703), Asian race (OR 0.756, 95% CI 0.660-0.867), and increasing recipient BMI (OR 0.982, 95% CI 0.977-0.994) after controlling for recipient age, number of embryos transferred on day 5, and unexplained infertility diagnosis. The proportion of multifetal deliveries was greater in cycles utilizing fresh (26.4%) vs. cryopreserved (20.6%) oocytes.

Conclusion(s): The live birth rate is higher with use of fresh oocytes vs. cryopreserved oocytes in fresh embryo transfer cycles. Negative live birth predictors include recipient Black non-Hispanic or Asian race and increasing BMI.

Keywords: Donor egg; IVF; fresh embryo transfer; live birth; oocyte recipient.