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

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.