Increased rates of complications in singleton pregnancies of women previously diagnosed with polycystic ovary syndrome predominantly in the hyperandrogenic phenotype.

Objective: To study the presence of several maternal and neonatal complications in a cohort of women with hyperandrogenic as well as normoandrogenic polycystic ovary syndrome (PCOS) and women with PCOS who received different fertility treatments.

Design: Prospective multicenter cohort study.

Setting: Hospitals and midwifery practices.

Patient(s): One hundred and eighty-eight women with PCOS and singleton pregnancies (study group) and 2,889 women with a naturally conceived singleton pregnancy (reference group).

Intervention(s): Observational study.

Main Outcome Measure(s): Maternal and neonatal pregnancy complications.

Result(s): Women with PCOS had a statistically significantly increased risk of developing gestational diabetes (adjusted odds ratio [AOR] 4.15; 95% confidence interval [CI], 2.07-8.33) compared with the reference group, and their infants were more often born small for gestational age (AOR 3.76; 95% CI, 1.69-8.35). In a subgroup analysis, maternal complications were statistically significantly more often present in women with hyperandrogenic (defined as a free androgen index >4.5) PCOS (n = 76; 40% of all PCOS women) compared with those with normoandrogenic PCOS (n = 97; 52% of all PCOS women) (45% vs. 24%; P=.003); no statistically significant differences were observed between these groups regarding neonatal complications.

Conclusion(s): Women with PCOS have an increased risk of maternal and neonatal pregnancy complications, especially women with the hyperandrogenic phenotype.

Clinical Trial Registration Number: NCT00821379.