In-vitro maturation of oocytes vs in-vitro fertilization with a gonadotropin-releasing hormone antagonist for women with polycystic ovarian syndrome: can superiority be defined?

OBJECTIVE: Patients with polycystic ovarian syndrome (PCOS) are at increased risk of ovarian hyperstimulation syndrome (OHSS) in controlled ovarian hyperstimulation cycles. Interventions to reduce the risk of OHSS in these patients include in-vitro fertilization (IVF) with a gonadotropin-releasing hormone (GnRH) antagonist, and retrieval of immature oocytes followed by in-vitro maturation (IVM). The aim of this study was to compare the outcomes of IVM and IVF-GnRH antagonist protocols in women with PCOS undergoing assisted reproductive technology.

STUDY DESIGN: Retrospective cohort study. Records of women with PCOS who underwent IVM or IVF-GnRH antagonist protocols between 2010 and 2011 were reviewed. In total, there were 61 IVM cycles and 53 IVF-GnRH antagonist cycles. The treatment protocols were compared in terms of the number of oocytes retrieved, dose of gonadotropin administrated, fertilization rates, quality of embryos, pregnancy, and delivery and abortion rates.

RESULTS: The number (mean±standard deviation) of mature oocytes did not differ significantly between the two groups (7.11±5.7 vs 8.16±5.07 for the GnRH antagonist group and the IVM group, respectively; p=0.38). The average dose of gonadotropin (1938 IU±838 IU/cycle vs 118±199 IU/cycle; p<0.001), fertilization rate (77% vs 60%; p<0.001) and high-quality embryo rate (58.8% vs 48.3; p<0.001) were significantly higher in the GnRH antagonist group compared with the IVM group. Pregnancy rates (40% vs 25%; p=0.08), livebirth rates per pregnancy (71% vs 53%; p=0.265) and abortion rates (10% vs 27%; p=0.17) were comparable.

CONCLUSIONS: The IVM protocol can be an alternative for infertile women with PCOS who wish to prevent the potential adverse effects of gonadotropin treatment. Prospective studies are needed to compare the outcomes of these two treatment protocols.