Oligoovulatory and Anovulatory Cycles in Women with Polycystic Ovary Syndrome (PCOS): What's the Difference?

Context: Polycystic ovary syndrome (PCOS) is a heterogeneous disorder. The phenotype may differ between patients who exhibit signs of recent ovulation and anovulatory PCOS patients. Objective: Our objective was to study differences in clinical and endocrine characteristics and response to ovulation induction (OI) treatment comparing oligoovulatory and anovulatory PCOS patients. Design and Setting: We conducted a retrospective cohort study at a tertiary hospital. Patients: PCOS patients (n = 1750) presenting with oligo-or amenorrhea were diagnosed according to the Rotterdam 2003 consensus criteria. Arbitrarily, oligoovulatory PCOS was defined by a single random serum progesterone level of 10 nmol/liter or higher. Main Outcome Measures: We evaluated the incidence of oligo-or amenorrhea, menstrual cycle length, serum androgen levels, follicle count, and OI outcome parameters. Results: Anovulatory women (n = 1541 of 1750, 88.1%) were more often amenorrheic (P < 0.001) and presented with a longer cycle duration (P < 0.001) compared with oligoovulatory women (n = 209 of 1750, 11.9%). Serum levels of testosterone (P < 0.001), the free androgen index (P < 0.001), and total follicle count (P < 0.005) were higher in anovulatory compared with oligoovulatory patients. During clomiphene citrate OI, more oligoovulatory women gained regular menstrual cycles (P < 0.05), whereas after second-line treatment with recombinant FSH, more anovulatory women became pregnant (P < 0.05). Conclusions: Oligoovulatory women with PCOS exhibit a milder phenotype of ovarian dysfunction and have a more favorable response to OI treatment using clomiphene citrate compared with anovulatory PCOS patients. However, during second-line treatment with recombinant FSH, anovulatory PCOS patients presented with a higher chance of pregnancy compared with oligoovulatory patients. (J Clin Endocrinol Metab 95: E485-E489, 2010)