Aging women with polycystic ovary syndrome who achieve regular menstrual cycles have a smaller follicle cohort than those who continue to have irregular cycles

Objective: To examine whether follicle loss due to ovarian aging is responsible for the occurrence of regular menstrual cycles in aging women with polycystic ovary syndrome (PCOS), the size of the FSH-sensitive follicle cohort was estimated by the exogenous follicle-stimulating hormone ovarian reserve test (EFORT) and related to the follicle count as measured by ultrasound. Design: Prospective study. Setting: Reproductive endocrinology unit of an academic medical center. Patient(s): Twenty-seven aging women with PCOS (35.8-49.4 years): 20 with regular menstrual cycles and 7 with oligomenorrhea or amenorrhea. Intervention(s): EFORT and transvaginal ultrasound. Main Outcome Measure(s): Baseline (cycle day 2, 3, or 4) FSH, androstenedione (A), T, E-2 and inhibin B levels, the E-2 and inhibin B increment after the EFORT, and the follicle Count. Result(s): After correction for the body mass index (BMI), the inhibin B increment was higher in the irregular menstrual group, but the E-2 increment did not differ significantly between the two groups. Ultrasound showed a median follicle count of 8.5 (4.0-18.0) in women with regular menstrual cycles (n = 16), compared with 18.0 (8.0-35.0) in irregularly menstruating women (n = 7). The follicle count was significantly correlated to the FSH-induced E-2 increment (r = 0.656) as well as to the inhibin B increment (r = 0.654). The regularly menstruating group was significantly older, had a higher basal FSH concentration. and had lower androgens than the irregularly menstruating group. Conclusion(s): The smaller follicle count, the older age, the higher FSH concentration, and the lower FSH-induced inhibin B increment found in women with PCOS and a regular menstrual cycle confirm that a decrease in the size of the follicle cohort due to ovarian aging is largely responsible for the regular menstrual cycles in aging PCOS women. (C) 2003 by American Society for Reproductive Medicine.