Developmental capacity of in vitro-matured human oocytes retrieved from polycystic ovary syndrome ovaries containing no follicles larger than 6 mm.

OBJECTIVE To test the developmental competence of oocytes in a nonhCG-triggered in vitro maturation (IVM) system when oocyte-cumulus complexes (OCC) are retrieved from antral follicles with a diameter of <6 mm. DESIGN Prospective cohort study. SETTING Tertiary university-based referral center. PATIENT(S) From January 2010 to September 2011, 121 patients with polycystic ovaries/polycystic ovary syndrome underwent 239 IVM cycles in total. In 58 of these cycles (44 patients), all antral follicles had a diameter of <6 mm on the day of oocyte retrieval. INTERVENTION(S) NonhCG-triggered IVM of oocytes, fresh or vitrified/warmed embryo transfer (ET). MAIN OUTCOME MEASURE(S) Oocyte diameter, maturation rate, fertilization rate, embryo development and morphology, implantation rate, clinical pregnancy rate, ongoing pregnancy rate. RESULT(S) Oocyte retrieval yielded 16.7 OCC/cycle, and 50.8% of oocytes completed IVM. The mean oocyte diameter increased from 108.8 ± 4.3 μm to 111.9 ± 4.1 μm after IVM. Mean fertilization rate was 63.7%, and 45.4% of 2-pronuclei oocytes developed into a morphologically good-quality embryo on day 3 after intracytoplasmic sperm injection. Fresh ET resulted in two ongoing pregnancies (2/37; 5.4%). Deferred vitrified-warmed ET led to an ongoing pregnancy rate of 34.6% (9/24). Three healthy babies were born and eight pregnancies were still ongoing. CONCLUSION(S) Oocytes retrieved from follicles with a diameter of <6 mm grow during a 40-hour IVM culture can acquire full competence in vitro, as illustrated by their development into healthy offspring. Endometrial quality appears to be a crucial determinant of pregnancy after nonhCG-triggered IVM.