Is elective single-embryo transfer a viable treatment policy in in vitro maturation cycles?

<bold>Objective: </bold>To compare the clinical outcome of single-embryo transfer (SET) with double-embryo transfer (DET) in in vitro maturation (IVM) cycles performed in patients with polycystic ovary syndrome (PCOS), and to determine which factors predict those outcomes.<bold>Design: </bold>A retrospective analysis.<bold>Setting: </bold>Private assisted reproduction center.<bold>Patient(s): </bold>One hundred and fifty-nine women with PCOS.<bold>Intervention(s): </bold>In vitro maturation with elective SET or DET conducted between September 2007 and May 2014.<bold>Main Outcome Measure(s): </bold>Live-birth rates.<bold>Result(s): </bold>Single-embryo transfer was performed in 83 patients (52.2%), and DET was performed in 76 patients (47.7%). When compared with the patients who had DET, the patients who had SET were statistically significantly younger (32.4 ± 3.5 vs. 24.1 ± 4.2 years) and had a shorter infertility duration (9.2 ± 4.5 vs. 4.4 ± 2.1 years), fewer previous ART cycles (<2 prior attempts, 39.5% vs. 6%; ≥2 prior attempts, 60.5% vs. 0), fewer collected oocytes (15.1 ± 4.6 vs. 12.6 ± 3.8), fewer metaphase II oocytes (9.0 ± 4.1 vs. 5.7 ± 2.9), fewer fertilized oocytes (8.2 ± 3.7 vs. 3.6 ± 2.3), and a higher implantation rate (27% vs. 47%). The SET and DET groups had similar embryo quality and similar clinical pregnancy (44.6% vs. 44.7%) and live-birth rates (34.9% vs. 34.2%). Twin pregnancy rates were statistically significantly higher in the DET compared with the SET groups (9.2% vs. 2.4%).<bold>Conclusion(s): </bold>In vitro maturation is a successful assisted reproduction technique that can be an alternative to conventional in vitro fertilization in women presenting with PCOS-related infertility. Our observations suggest that SET is a feasible option to prevent multiple pregnancies while maintaining the live-birth rate. [ABSTRACT FROM AUTHOR]