The degree of serum estradiol decline in early and midluteal phase had no adverse effect on IVF/ICSI outcome

BACKGROUND: Estradiol levels fall rapidly in the luteal phase of ART cycles. So far, the effect of this estradiol decline on pregnancy outcome has remained controversial. AIM: To study the effect of early and midluteal estradiol decline on pregnancy and miscarriage rate. We also sought to determine whether estradiol fall was related to increased risk of bleeding per vagina in the first trimester among pregnancies which crossed 12 weeks. SETTING: Tertiary Assisted conception center. DESIGN: Retrospective study. MATERIALS AND METHODS: We analyzed data of 360 consecutive patients who underwent IVF-ET/ICSI cycles using one of the three protocols: Midluteal downregulation, short flare, and antagonist protocol. STATISTICAL METHODS: Statistical evaluation was performed with the Student's t test, Chi square, Fischer's exact test, analysis of variance, and Mann-Whitney tests were appropriate using SPSS for Windows, Standard version 11.0. RESULTS: The mean % EL-E2 and % ML-E2 declines were not significantly different in the pregnant and nonpregnant groups when analyzed separately in the three protocols. Also, the degree of midluteal estradiol decline did not correlate with pregnancy outcome. Moreover, the mean % early and midluteal estradiol decline did not differ significantly in patients with preclinical, clinical abortions, and ongoing pregnancy. The estradiol decline was not found to influence the risk of bleeding in the first trimester. CONCLUSIONS: Our results show that the degree of estradiol fall in the luteal phase of ART cycles does not influence pregnancy and first trimester miscarriage rate.