The impact of timing for estrogen supplementation in polycystic ovary syndrome patients undergoing primed in vitro maturation

Objective This study aims to determine the effects of early and late onset estrogen supplementation on the immature oocyte retrieval, fertilization and clinical pregnancy rates in follicle stimulating hormone (FSH) and human chorionic hormone (hCG) primed in vitro maturation (IVM) cycles of the patients with polycystic ovary syndrome (PCOS). Methods This is a retrospective analysis of 161 patients with PCOS who underwent FSH and hCG primed IVM. Group 1 included 120 patients who received early onset estrogen supplementation while group 2 consisted of 41 patients who had late onset estrogen supplementation in primed IVM cycles. Immature oocyte (germinal vesicle and/or metaphase I) retrieval and fertilization rates were the primary outcomes, whereas clinical pregnancy and live rates were the secondary outcomes. Results Group 1 patients had significantly higher body mass index and more previous IVF attempts (p = 0.001 and p = 0.008, respectively). All of the retrieved oocytes from the PCOS patients were either germinal vesicle or metaphase I oocytes and there were no metaphase II oocytes among the retrieved oocytes. Both groups had statistically similar numbers of metaphase I and fertilized oocytes (p > 0.05 for both). However, group 1 patients had significantly lower number of germinal vesicle oocytes but significantly higher number of metaphase II oocytes (p = 0.001 for both). Both groups had statistically similar fertilization (85.0% vs 78.0%), clinical pregnancy (49.2% vs 43.9%) and live birth (37.5% vs 39.0%) rates (p > 0.05 for all). Conclusion Early onset estrogen supplementation appears to improve the quality of retrieved immature oocytes and contribute to the maturation of oocytes in stimulated IVM cycles.