Abstract
OBJECTIVE: The aim of this study was to investigate the extent to which self-reported menstrual cycle length during reproductive years is associated with menopausal symptoms and age at natural menopause at midlife. METHODS: This analysis includes 634 women who enrolled in Project Viva during pregnancy (1999-2002) and completed the midlife visit approximately 18 years later. Women self-reported menstrual cycle length at enrollment (early pregnancy) and at midlife reported total and specific menopausal symptoms using the Menopause Rating Scale as well as age at natural menopause. We used linear and regression models to evaluate associations of cycle length with total and specific menopausal symptoms. We also applied a time-to-event Cox proportional hazards model to investigate the relationship between menstrual cycle length and onset of natural menopause. We adjusted models for age at midlife visit, prepregnancy body mass index, race/ethnicity, education, and parity. RESULTS: At enrollment (median age, 33.3 years), 90 (14%) women reported having short (≤25 days) and 39 (6%) reported long (≥35 days) menstrual cycles. Compared with women with a normal menstrual cycle length of 26 to 34 days, women whose cycles were short had a higher total Menopause Rating Scale at midlife ( β = 2.05; 95% confidence interval [CI], 0.73-3.38). Specifically, women with short menstrual cycles during their reproductive years had higher odds of midlife sleep problems (odds ratio [OR], 1.92; 95% CI, 1.10-3.37), heart discomfort (OR, 1.68; 95% CI, 1.03-2.73), and depressive symptoms (OR, 1.85; 95% CI, 1.16-2.96). In addition, compared with women with a normal cycle length of 26 to 34 days, women reporting short cycles had an earlier onset of natural menopause (hazard ratio, 1.67; 95% CI, 1.11-2.51). CONCLUSIONS: Compared with women with normal menstrual cycle length, those with short menstrual cycles during their reproductive years had a higher frequency of total and certain menopausal symptoms at midlife and reached menopause earlier.