REPRODUCTIVE AGING - ACCELERATED OVARIAN FOLLICULAR DEVELOPMENT ASSOCIATED WITH A MONOTROPIC FOLLICLE-STIMULATING-HORMONE RISE IN NORMAL OLDER WOMEN

Women experience a decline in fertility that precedes the menopause by several years. Previous studies have demonstrated a monotropic rise i n FSH associated with reproductive aging; however, the mechanism of th is rise and its role in the aging process are poorly understood. The p urpose of this study was to characterize ovarian follicular developmen t and ovarian hormone secretion in older reproductive age women. Sixte en women, aged 40-45 yr, with regular ovulatory cycles were studied. T he control group consisted of 12 ovulatory women, aged 20-25 yr. Serum obtained by daily blood sampling was analyzed for FSH, LH, estradiol (E), progesterone, and inhibin (Monash polyclonal assay). Follicle gro wth and ovulation were documented by transvaginal ultrasound. Older wo men had significantly higher levels of FSH throughout the menstrual cy cle. E, progesterone, LH, and inhibin levels did not differ between th e two age groups when compared relative to the day of the LH surge. Ul trasound revealed normal growth, size, and collapse of a dominant foll icle in all subjects. Older women had significantly shorter follicular phase length associated with an early acute rise in follicular phase E, reflecting accelerated development of a dominant follicle. We concl ude that older reproductive age women have accelerated development of a dominant follicle in the presence of the monotropic FSH rise. This i s manifested as a shortened follicular phase and elevated follicular p hase E. The fact that ovarian steroid and inhibin secretion were simil ar to those in the younger women suggests that elevated FSH in women o f advanced reproductive age may represent a primary neuroendocrine cha nge associated with reproductive aging.