Maternal and neonatal outcomes in pregnant women with PCOS: comparison of different diagnostic definitions

STUDY QUESTION: Does the prevalence of adverse maternal and neonatal outcomes vary in women diagnosed with polycystic ovary syndrome (PCOS) according to different definitions? SUMMARY ANSWER: A comparison of different criteria revealed that there is a substantial risk for perinatal complications in PCOS women, regardless of the used definition. WHAT IS KNOWN ALREADY: Pregnant women with PCOS are susceptible to perinatal complications. At present, there are three main definitions for PCOS. So far, we are aware of only one study, which found that the elevated risk for complications varied widely depending on the different phenotypes and features but only considered a relatively small sample size for some of the phenotypes. STUDY DESIGN, SIZE, DURATION: Retrospective matched cohort study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data of primiparous women with PCOS according to ESHRE/ASRM 2003 criteria and healthy controls giving birth to neonates >= 500 g were included. A total of 885 women were analysed: out of 177 women with PCOS, 85 (48.0%) met the National Institutes of Health (NIH) 1990 criteria, another 14 (7.9%) featured the additional phenotypes defined by The Androgen Excess and PCOS Society (AE-PCOS) 2006 criteria, 78 (44.1%) were classified as PCOS exclusively by the ESHRE/ASRM 2003 definition, and 708 represented the control group. MAIN RESULTS AND THE ROLE OF CHANCE: The prevalence of adverse maternal (49.4 versus 64.3 versus 60.3%, P = 0.313) and neonatal (27.1 versus 35.7 versus 23.1%, P = 0.615) outcomes did not differ within the three PCOS groups (ESHRE/ASRM, NIH, AE-PCOS, respectively). Compared with healthy controls, the risk for maternal complications was increased in PCOS patients [odds ratio (OR) 2.57; 95% confidence interval (CI) 1.82-3.64; P < 0.001] while there was no difference in neonatal complications (OR 0.83; 95% CI 0.56-1.21; P = 0.343). LIMITATIONS, REASONS FOR CAUTION: A limitation of our study is its retrospective design and the relatively small sample size, particularly in the AE-PCOS subgroup. WIDER IMPLICATIONS OF THE FINDINGS: Since women with PCOS have, regardless of the used definition, a high risk of maternal and neonatal complications they should be informed and advised to follow regular checks in units where problems can be detected early to allow specialized care.