OBJECTIVE: To investigate the association between polycystic ovary syndrome (PCOS) and the rate of embryo development, using time-lapse monitoring systems, compared with a control group of women with mechanical (tubal) factor infertility. DESIGN: A retrospective case-control study conducted in a university-affiliated in vitro fertilization (IVF) unit. PATIENTS: Women with PCOS undergoing IVF treatments and those with non-PCOS controls with tubal factor infertility only. Development morphokinetic milestones were compared and analysis of covariance for time to distinct cell number as well as logistic mixed models to determine predictors for embryos over the 75th percentile was performed. EXPOSURE: Not applicable. MAIN OUTCOME MEASURES: Embryo development morphokinetic parameters in women with and without PCOS undergoing IVF treatments. RESULTS: The study included 791 embryos from 115 women, 364 embryos from 52 women with PCOS and 427 embryos from 63 women with non-PCOS controls with tubal factor infertility. The PCOS group was 4 years younger (30.07 ± 6.03 vs. 34.08 ± 4.84 years) and had higher number of oocytes retrieved (16.00 vs. 11.00), mature oocytes (11.00 vs. 7.00) and fertilized oocytes (8.00 vs. 5.00). The PCOS and control groups demonstrated comparable clinical pregnancy rates (55.8% vs. 32.1%), miscarriage rate (12.5% vs. 11.8%), and live birth rate (48.8% vs. 31.2%). Morphokinetic parameters were comparable between the groups. Although age was associated with later time to 5 and 8 discrete cells and start of blastulation (tSB), PCOS was only associated with later tSB, including tSB >
75th percentile. CONCLUSION: This study demonstrated comparable IVF outcomes in women with PCOS and non-PCOS controls. An analysis of time-lapse monitoring data from these patients showed no evidence that PCOS negatively affects embryonic development rate in women undergoing IVF cycles.