Objective: To compare the odds of a good perinatal outcome between cryopreserved and fresh donor oocytes.
Methods: We used the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System to conduct a retrospective cohort study of women undergoing donor oocyte in vitro fertilization (IVF) from 2012 to 2015. Cycles using cryopreserved embryos, a gestational carrier, or preimplantation genetic testing were excluded. The primary outcome was a good perinatal outcome, defined as a singleton live birth at 37 weeks of gestation or more with birth weight at or within 2,500 g and 4,000 g. Secondary outcomes included live birth, multiple birth, and prematurity. Generalized estimating equation models were used to test the effect of oocyte type on the primary outcome while accounting for covariates and the correlation induced by repeated cycles within a patient.
Results: Of the 36,925 cycles included in the analysis, 8,381 (22.7%) used cryopreserved and 28,544 (77.3%) used fresh oocytes. The odds of a good perinatal outcome were marginally but significantly lower with cryopreserved than with fresh oocytes before and after covariate adjustment (22.0% vs 24.1%, unadjusted odds ratio [OR] 0.90, 95% CI 0.85-0.96, adjusted OR 0.88, 95% CI 0.81-0.95). Compared with fresh oocytes, cryopreserved oocytes were associated with lower rates of live birth (39.6% vs 47.7%, OR 0.75, 95% CI 0.72-0.79), multiple birth (22.3% vs 31.2%, OR 0.63, 95% CI 0.58-0.69), and prematurity (27.6% vs 30.6%, OR 0.86, 95% CI 0.79-0.94).
Conclusion: This retrospective national study demonstrated that the use of cryopreserved compared with fresh donor oocytes in IVF cycles is associated with marginally lower odds of a good perinatal outcome.