Age at menopause and childbearing patterns in relation to mortality.

Several studies have reported increased mortality risk with early natural menopause. More recently, mortality risk was reported to be reduced among women who gave birth at age > or =40 years. The association between reproductive history and mortality was explored among 826 women in a prospective study involving 18,959 person-years of follow-up (from age 50 to 1990-1991) and 108 deaths. After adjustment for age and other covariates, the risk ratio among parous women was 1.53 (95% confidence interval: 0.58, 4.07) for natural menopause at age < or =45 years compared with > or =51 years. In contrast to a previous report, however, the highest estimated mortality risk was seen among women who gave birth in their forties (adjusted risk ratio = 2.14, 95% confidence interval: 1.05, 4.38) compared with having a last birth at ages 30-34 years.