Purpose: To investigate the impact of late follicular phase serum estradiol (E2) levels on implantation and pregnancy outcomes of cleavage stage cryopreserved/thawed embryos transferred in programmed cycles with exogenous hormonal replacement.
Methods: Retrospective cohort analysis of IVF patients with transfer of cryopreserved-thawed day-3 embryos in E2 and progesterone (P4) supplemented cycles (n = 208 cycles).
Main outcome measures: implantation and pregnancy rates according to late follicular phase serum E2 levels and early secretory phase E2/P4 ratios.
Results: Logistic regression performed for embryo implantation and for pregnancy outcome in relation to E2 (day 15), P4 (day 15 and 16), before (crude analysis) and after adjustment (adjusted analysis) for baseline characteristics (including age, BMI, serum basal cycle day 3 FSH levels, embryo quality, endometrial lining thickness) showed no significant association. Similarly, ROC analysis showed no impact of cycle day 16 E2/P4 ratio.
Conclusions: Neither late follicular phase serum E2 nor the early E2/P4 ratio were able to predict implantation or pregnancy outcome of day-3 cryopreserved-thawed embryos transferred in artificially programmed cycles.