A "freeze-all" embryo strategy after in vitro maturation: a novel approach in women with polycystic ovary syndrome?

OBJECTIVE: To assess the efficiency of a "freeze-all" embryo strategy after immature oocyte retrieval (OR) and in vitro maturation (IVM) in patients with polycystic ovary syndrome (PCOS).
DESIGN: Retrospective case series. SETTINGS: University-based tertiary referral center. PATIENT(S): Seventy-nine consecutive PCOS patients undergoing IVM followed by vitrified-warmed embryo transfer (ET) over a 2-year period. INTERVENTION(S): All patients received 150 IU/d highly purified hMG for 3 consecutive days. There was no hCG trigger given before OR. All day-3 embryos of good morphologic quality were vitrified. Single or double ET was performed in 114 consecutive artificial cycles. The cumulative live birth rate (LBR) per patient was calculated, as well as the projected cumulative LBR. MAIN OUTCOME MEASURE(S): LBR per patient and per retrieved immature oocyte. RESULT(S): Mean age, body mass index, and antimüllerian hormone were 28.5 ± 3.5 years, 27.8 ± 7.1 kg/m(2), and 10.3 ± 5.5 μg/L, respectively. In total, 1,526 cumulus-oocyte complexes were retrieved. IVM yielded 800 metaphase II oocytes (52.4%), and 291 day-3 embryos were cryopreserved. Of these, 224 (76.9%) embryos were warmed. One hundred seventy-one survived (76.3%), and 105 ETs were performed. LBR per ET was 16.2% and the cumulative LBR per patient was 21.8%. LBR per retrieved immature oocyte was 1.1%. The projected LBR per patient was 24.2%. CONCLUSION(S): IVM followed by a "freeze-all" embryo strategy is a novel approach for women with PCOS. Patients who undergo IVM should be advised that each immature oocyte retrieved yields a 1.1% chance to achieve a live birth.