Body size at birth, early-life growth and the timing of the menopausal transition and natural menopause.

BACKGROUND:Whether birth weight and early-life growth are associated with age at menopause has not been resolved. METHODS:We conducted a prospective study in two U.S. birth cohorts to investigate the relation of weight at birth and weight and growth trajectory through age 4 years to menstrual status among 1001 women ages 39-49 years. We used logistic regression models with GEE. RESULTS:Women who weighed more at birth and at one year were less likely to have experienced the menopausal transition or natural menopause by age 39-49 years (odds ratio(OR) = 0.50, 95% confidence interval(CI) = 0.32, 0.77 and OR = 0.82, 95%CI = 0.68, 0.99 per kilogram increase at birth and age one, respectively). CONCLUSIONS:Women who had a lighter weight at birth and women who were lighter than their peers through infancy experienced the menopausal transition or natural menopause at an earlier age.