High Peak Estradiol/Mature Oocyte Ratio Predicts Lower Clinical Pregnancy, Ongoing Pregnancy, and Live Birth Rates in...

To define the relationship between peak estradiol (E2)/mature oocyte ratio and pregnancy outcomes in gonadotropin-releasing hormone (GnRH) antagonist intracytoplasmic sperm injection (ICSI) cycles.

Retrospective cohort study in the setting of an academic reproductive medicine practice. Records from 162 fresh, autologous, GnRH antagonist ICSI cycles performed between 2009 and 2012 .were analyzed. The main outcome measures were rates of clinical pregnancy (CPR), ongoing pregnancy (OPR), and live birth (LBR).

For the primary analysis, 4 groups were created based on peak E2/mature oocyte ratio (group 1: <200, group 2: 200-300, group 3: 300-400, and group 4: >400 pg/mL/oocyte). After adjusting for age, basal FSH, and the number of mature oocytes, a significantly lower OPR was seen in group 4 as compared to group I (OR 0.15, 95% CI 0.03-0.86; p=0.032) and group 3 (OR 0.17, 95% CI 0.03-0.98; p=0.048), respectively. The adjusted LBR was also significantly lower in group 4 as compared to group 1 (OR 0.15, 95% CI 0.03-0.83; p=0.030). In a secondary analysis, 3 ranges of peak E2/ mature oocyte ratio (<200, 200-400, and >400 pg/ mL/oocyte) were compared between low, normal, and high responders (<6, 6-15, and >15 mature oocytes, respectively). Clinical pregnancy rate, OPR, and LBR were all lower in normal responders when the E2/oocyte ratio exceeded 400 pg/mL/oocyte as compared to <200 pg/mL/oocyte and 200-300 pg/mL/oocyte (CPR 1% vs. 16% and 32%, respectively, p=0.017; OPR 0 vs. 15% and 27%, respectively, p=0.011; and LBR 0 vs. 13% and 26%, respectively, p=0.018).

Very elevated peak E2/mature oocyte ratio is associated with a lower CPR, OPR, and LBR in fresh, autologous, GnRH antagonist ICSI cycles.