Effect of estrace on pregnancy rates for women with thin endometrial lining undergoing intrauterine insemination

Abstract

Listen

Translate article

To evaluate the effect of exogenous estradiol on pregnancy rates for women with thin endometrial lining undergoing intrauterine insemination (IUI) as compared to women who did not receive estradiol for endometrial support; we hypothesize that there was no difference in pregnancy rates between the two groups. Retrospective chart review. All IUI cycles completed at Stanford University Clinic for Reproductive Medicine from March-December 2017 were reviewed. All monitored IUI cycles were included. Cycles with the addition of exogenous estradiol given vaginally or orally were compared to those without exogenous estradiol. Differences in endometrial parameters, pregnancy rates, miscarriage rates and live birth rates were compared between both groups. A total of 885 IUI cycles were included. In 85 cycles, exogenous estradiol was initiated for thin endometrium. Baseline characteristics including maternal age, body mass index, ethnicity, number of IUI cycles per patient, type of IUI cycle, and total motile sperm count were similar between the two groups. Mean baseline endometrial lining was thicker in the non-estradiol group, and the non-estradiol group was more likely to have a diagnosis of unexplained infertility whereas the estradiol group was more likely to have a diagnosis of diminished ovarian reserve. Despite initiation of estradiol, the mean endometrial thickness at trigger scan remained significantly thinner in estradiol group as compared to the non-estradiol group (6.4±1.3 cm vs. 8.4±1.9 cm, respectively, p <0.001), although the change in thickness in the estradiol group from baseline to trigger scan did increase on average by 2.2 cm. Pregnancy, miscarriage and live birth rates were similar between the estradiol and non-estradiol groups (see Table 1).Table 1OutcomesEstradiol (n=85)No Estradiol (n=800)P-valueEndometrial Lining thickness (cm), mean±standard errorBaseline4.2±1.34.9±1.7<0.001Estradiol initiation4.9±0.86.4±1.7<0.001Trigger6.4±1.38.4±1.9<0.001Pregnancy Rate, n (%)14 (20%)81 (10%)0.12Spontaneous Abortions, n (%)8 (10%)30 (4%)0.08Live births to date, n (%)5 (10%)42 (10%)0.78 Open table in a new tab Although there is limited data supporting the use of exogenous estradiol to improve outcomes during IUI cycles, this low risk intervention is often employed in the setting of a thin endometrial lining in the late follicular phase. In women undergoing IUI with exogenous estradiol supplementation due to thin endometrial lining, pregnancy, miscarriage and live birth rates were similar to women undergoing IUI without exogenous estradiol use.