Longitudinal changes in hypothalamic and ovarian function in perimenopausal women with anovulatory cycles: relationship with vasomotor symptoms.

OBJECTIVE: To determine whether the transition to menopausal status is unidirectional and predictable with aging.
DESIGN: Longitudinal evaluation of the menstrual cycle hormone patterns and experience of vasomotor symptoms in an anovulatory, perimenopausal cohort, during cycles that occurred 1 and 2 years after an anovulatory cycle.
SETTING: Academic center. PATIENT(S): One hundred fifty-nine of 840 women in the Daily Hormone Study, a substudy of the Study of Women's Health across the Nation (SWAN), had anovulatory cycles. Their menstrual cycle patterns were previously described. This report describes their cycle patterns and vasomotor symptoms in the subsequent 2 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Daily urinary hormone levels of FSH, LH, and estrogen and P metabolites and reports of daily occurrence of vasomotor symptoms. RESULT(S): While a tendency to develop cycles having a loss of negative feedback of estrogen on LH secretion was seen before menopause, there is no clear progression of cycle patterns in anovulatory women. Anovulation did not predict menopause within 2 years. Vasomotor symptoms occur before menopause, as experienced by 73% of the women. Vasomotor symptoms were not related to cycle pattern. CONCLUSION(S): Any cycle pattern may be related to vasomotor symptoms. The best predictor of vasomotor symptoms is a prior history of vasomotor symptoms.