Elevated Serum Estradiol Levels Do Not Inhibit Implantation During Frozen Embryo Transfer Cycles

The aim of the study is to determine if the magnitude of serum estradiol levels in blastocyst frozen embryo transfer cycles are associated with clinical pregnancy. A retrospective cohort study of female patients 18-43 years old, who underwent vitrified blastocyst embryo transfers at Tripler Army Medical Center from October 1, 2006, to October 1, 2016, was evaluated to determine the impact of estradiol levels on ongoing pregnancy rates in frozen embryo transfer cycles. The study included 173 total frozen embryo transfer cycles during the 10-year study period. The mean age at time of transfer was 34.5 years old (±4.4) with a majority of women undergoing double embryo transfer (70%). There was no statistical difference in ongoing pregnancy rates across estradiol levels (p = 0.80). However, at estradiol levels >3000 pg/mL, a statistically significant ongoing pregnancy rate was observed (p = 0.009). Ongoing pregnancy rate in frozen embryo transfer cycles is not negatively impacted by elevated estradiol levels.