Associations of gestation length and offspring birthweight for gestational age with menopausal symptoms and age of natural menopause at midlife among women enrolled in a prebirth longitudinal cohort.

Objective: Reproductive history may help identify women at higher risk for experiencing menopausal symptoms. We hypothesized that gestation length and offspring birthweight for gestational age z-scores would be associated with menopausal symptoms and age at natural menopause in midlife among women in a longitudinal prebirth cohort.

Methods: Among 691 women enrolled in pregnancy and followed to midlife, we examined associations of gestation length and offspring birthweight for gestational age z-score at the index pregnancy with total menopausal symptoms assessed with the 11-item Menopause Rating Scale (MRS) using linear regression models, with individual menopausal symptoms using binomial regression models with a log link function, and with age at natural menopause using Cox proportional hazards models. We adjusted all models for age at enrollment, education, parity, annual household income, and prepregnancy body mass index.

Results: Mean (SD) MRS total score was 7.9 (5.8) points at age 52.1 (3.8) years, and mean (SD) age at natural menopause was 50.8 (3.7) years. We observed null associations of gestation length (β = -0.07 points per week, 95% confidence interval [CI] = -0.32 to 0.18) and birthweight for gestational age z-score (β = 0.16 points per z-score, 95% CI = -0.31 to 0.63) with the MRS total score in adjusted models. We also observed null associations of gestation length (adjusted hazards ratio = 0.99 per week, 95% CI = 0.94-1.06) and birthweight for gestational age z-score (adjusted hazards ratio = 1.06 per z-score, 95% CI = 0.94-1.19) with age of onset of natural menopause.

Conclusions: Birth outcomes were not associated with total menopause symptom scores or age at natural menopause.