Lifetime cognitive function and timing of the natural menopause.

BACKGROUND: There is evidence that ovarian steroids influence both reproductive aging and neural development. OBJECTIVE: We investigated the relationship between menopause and lifetime cognitive function in a prospective birth cohort study. METHODS: Participants were 1,572 women enrolled in the Medical Research Council National Survey of Health and Development (the British 1946 birth cohort). By age 50, 245 women were postmenopausal, 724 were pre- or perimenopausal, 288 had had a hysterectomy or bilateral oophorectomy, and 291 women had started taking hormone replacement therapy (HRT) before their menopause. The remaining 24 women, for various reasons, could not be classified into any of these groups. We investigated the association between cognitive function at ages 8, 11, 15, 26, and 43 years and menopause timing using Cox proportional hazard models, censoring for hysterectomy and bilateral oophorectomy, and initially for HRT use. The effect of including HRT use before menopause as an additional outcome was investigated using a competing risks analysis. RESULTS: Higher cognitive scores were associated with later menopause. The effect was strongest in childhood. This finding could not be explained by a variety of potential confounders, including early social background, physical development, education, adult social class, parity, smoking, and alcohol consumption. CONCLUSIONS: Childhood cognitive function is related to timing of the natural menopause. Both may be influenced by ovarian steroids across the life-span.