Maternal pre-pregnancy BMI, gestational weight gain, and age at menarche in daughters

Objectives: Low birth weight, rapid postnatal growth, and high childhood BMI are associated with earlier menarche in girls. Associations between maternal pregnancy experience and daughters' age at menarche are less understood. In this study, we examine whether maternal pre-pregnancy BMI and gestational weight gain are related to the timing of menarche in daughters. Methods: The sample includes 2,181 mother-daughter pairs from the 1979 National Longitudinal Survey of Youth, a prospective cohort study. Survival analysis with Cox proportional hazards was used to estimate whether maternal pre-pregnancy overweight and obesity (BMI≥25.0 kg/m2) and gestational weight gain adequacy (categorized as inadequate, recommended, and excessive based on 2009 Institute of Medicine guidelines) were associated with risk of earlier menarche among girls, controlling for important covariates. Results: Maternal pre-pregnancy overweight and obesity were associated with daughters' earlier menarche (HR= 1.20, 95% CI 1.05-1.38). Excess gestational weight gain was not associated with daughters' age at menarche (HR=1.10, 95% CI 0.97, 1.25) in the adjusted model, nor was inadequate gestational weight gain (HR=1.05, 95% CI 0.92, 1.19). Consistent with past literature, earlier maternal age at menarche, Hispanic and black race, and lower parental education were all associated with an increased risk of earlier menarche in daughters. Conclusions: Maternal pre-pregnancy overweight and obesity is associated with an earlier menarcheal age in offspring. Further research is warranted to elucidate the pathways through which this relationship may operate. Gestational weight gain adequacy was not associated with menarcheal timing in this study after controlling for key covariates.