Pregnancy Outcomes after Frozen Embryo Transfer and Fresh Embryo Transfer in Women of Advanced Maternal Age: Single-Center Experience.

Delayed childbearing leads to increased assisted reproductive technology use by women of advanced maternal age (AMA). It is unclear whether fresh or frozen embryo transfer (FET) is the better option. We aimed to assess maternal and neonatal outcomes in patients having their first FET after a freeze-all cycle versus those having their first fresh embryo transfer (ET). We reviewed 720 women of AMA undergoing a first fresh ET (n = 375) or FET (n = 345) between January 2016 and April 2021. No significant difference in the live birth rate was found between FET and fresh ET (19.7% vs. 24.3%, = 0.141). The clinical pregnancy rate was significantly lower in the FET group than in the fresh ET group (26.4 % (91/345) vs. 33.6% (126/375), = 0.035), but FET resulted in higher birthweights (3217.16 ± 734.44 vs. 3003.37 ± 635.00, = 0.037) and was associated with a lower incidence of preterm births (2.6% vs. 5.6%, = 0.046). The risks of other maternal and neonatal outcomes did not differ significantly between the groups. Among women of AMA, the transfer of frozen embryos did not result in significantly higher rates of live birth than fresh embryos did; however, a freeze-all strategy may not be beneficial for the women of AMA.