Ultrasound Characterization of Disordered Antral Follicle Development in Women with Polycystic Ovary Syndrome

Abstract

Abstract Context The mechanism of oligo-anovulation in polycystic ovary syndrome (PCOS) is unknown. Objectives To evaluate follicular and endocrine characteristics of anovulatory and sporadic ovulatory cycles in women with PCOS. Design Prospective, longitudinal study. Setting Academic clinical research unit. Participants 26 reproductive-aged women (18-38 years) with PCOS, observed during natural anovulatory (PCOS-Anov; n = 12) and sporadic ovulatory cycles (PCOS-Ov; n = 14), and 12 controls. Interventions Transvaginal ultrasonography and venipuncture were performed every other day for 4 to 6 weeks in women with PCOS or at 1 interovulatory interval in control subjects. Main Outcome Measures Follicle number and diameter (ie, ≥2 mm) were quantified at each visit. Individual growth profiles were assessed for all follicles that grew to ≥7 mm. Blood samples were assayed for follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone. Results Follicular excess, or heightened follicle number versus controls, was observed across anovulatory and sporadic ovulatory cycles in PCOS. In PCOS-Anov, follicles emerged cyclically in some women (6/12; 50%) and continuously in others (6/12; 50%), then grew to a mean maximum diameter of 7.2 mm and regressed within 4.7 days. In PCOS-Ov, follicles mostly emerged cyclically as part of a cohort and dominant follicles showed normal growth to ovulation—albeit mean and maximum luteal progesterone concentrations were significantly lower versus controls. Conclusions Follicle growth and regression were detected on ultrasonography amidst perpetual follicular excess in PCOS. Documentation of continuous follicle recruitment and turnover, the absence of persistence, and altered luteal progesterone following sporadic ovulation, provide formative data on antral follicle development in PCOS.