How low is too low? Cycle day 28 estradiol levels and pregnancy outcomes.
Academic Article
Overview
abstract
OBJECTIVE: To determine the utility of cycle day 28 estradiol (E2) levels in predicting pregnancy outcomes after IVF. DESIGN: Retrospective, cohort study. SETTING: Academic medical center. PATIENT(S): All IVF cycles resulting in a positive pregnancy test result at our center between January 2007 and December 2012 were included. INTERVENTION(S): In vitro fertilization with fresh embryo transfer. MAIN OUTCOME MEASURE(S): A total of 5,471 IVF cycles were identified. Cycles were stratified by day-28 E2 level (pg/mL) into three groups: A: ≤50; B: 51-100; and C: >100. Outcomes measured were live birth, clinical pregnancy, biochemical, ectopic, and spontaneous abortion rates. RESULT(S): There were 806, 588, and 4,077 IVF pregnancies in groups A, B, and C, respectively. Live birth rates were lower in groups A (15.4%) and B (41.2%) compared with group C (77.4%), representing decreased odds of live birth in patients with E2 levels of ≤50 pg/mL (odd ratio 0.05, 95% confidence interval 0.04-0.07) and in patients with levels of 51-100 pg/mL (odds ratio 0.20, 95% confidence interval 0.17-0.25) compared with patients with levels >100 pg/mL. Rates of biochemical and ectopic pregnancies were higher in groups A (66.5%, 6.20%) and B (30.7%, 3.57%) compared with group C (7.31%, 0.66%). An hCG level <50 mIU/mL was associated with increased odds of a biochemical pregnancy and decreased odds of a live birth. CONCLUSION(S): Low E2 levels early in IVF pregnancies are associated with poorer pregnancy outcomes. Estradiol can be used alone or in conjunction with hCG levels to predict the odds of a live birth.
