Objective: To describe the distribution of E2 change after antagonist treatment and evaluate the prognostic implications on cycle outcomes.
Study design: We reviewed all antagonist IVF cycles from 2002 to 2007 in a university clinic, if E2 levels preantagonist and postantagonist administration were available (N = 287). Distributions of E2 response (defined as posttreatment/pretreatment E2 ratio) to antagonist treatment were composed and categorized by quartiles, and outcomes were analyzed (oocyte yield, clinical pregnancy and live birth rates).
Results: Cycles in the upper quartile had higher oocyte yield (15.2 +/- 7.5 vs. 13.1 +/- 7.9 vs. 11.8 +/- 5.6, upper, middle and lower quartiles, p<0.01), clinical pregnancy (45.9% vs. 28.7% vs. 25.0%, p=0.01) and live birth rates (38.6% vs. 22.3% vs. 20.0%, p=0.02) than cycles in middle and lower quartiles. However, cycles in the lowest quartile did not have significantly different outcomes from the majority of cycles in the cohort (middle quartiles of E2 distribution).
Conclusion: Our study suggests that E2 rise after antagonist initiation is positively associated with higher oocyte yield and clinical pregnancy. However, women with the lowest increases in E2 do not have significantly worse outcomes than most women using antagonist IVF protocols.