Concept: Ovaries meeting criteria for polycystic ovary morphology during peak reproductive years may no longer meet the criteria with age.
Objective: Ovarian volume and follicle number decrease with age in women with polycystic ovary syndrome (PCOS), permitting age-dependent criteria for PCOM.
Design and setting: We conducted longitudinal (7-15 year interval) and cross-sectional studies to examine polycystic ovarian morphology over time at an outpatient clinic and pathology laboratory in a tertiary care hospital.
Patients: Subjects included those with PCOS defined by the National Institutes of Health criteria (n = 11 and 483 for longitudinal and cross-sectional, respectively) and control women with regular menstrual cycles and no hyperandrogenism (n = 15 and 367), age 18-64 yr.
Interventions: Subjects underwent an ovarian ultrasound by a single observer.
Main outcome measures: Ovarian volume and follicle number were measured and ultrasound findings confirmed by a pathologist in a subset (n = 9).
Results: Ovarian volume (15.2 +/- 7.4 vs. 7.1 +/- 3.7 ml; P < 0.01) and follicle number (12.8 +/- 3.2 vs. 8.1 +/- 3.9; P < 0.05) decreased longitudinally in PCOS and control women (volume 11.6 +/- 4.4 vs. 5.4 +/- 2.2 ml and follicle number 8.3 +/- 1.9 vs. 6.3 +/- 1.8; both P < 0.005). Using cross-sectional data, log ovarian volume and follicle number decreased in both groups, but the decrease in log ovarian volume was less pronounced in women with PCOS than in controls (P < 0.01). A combination of age, log ovarian volume, follicle number, and testosterone distinguished PCOS subjects from controls with a receiver operator characteristic curve area of 0.90.
Conclusions: Ovarian volume and follicle number decrease with age in women with PCOS and controls necessitating age-based criteria to define polycystic ovarian morphology. It is possible to use these criteria to distinguish PCOS in women over age 40 yr.