The effect of parity on cause-specific mortality among married men and women.

The objective of this study was to examine mortality differentials among men and women by parity for deaths from cardio-vascular disease (CVD), cancer and other causes. The census-based Israel Longitudinal Mortality Study II (1995-2004) was used to identify 71,733 married men and 62,822 married women (45-89 years). During the 9-year follow-up period, 19,347 deaths were reported. Cox proportional hazard models adjusted for age, origin, and social class were used. A non-linear association between parity and CVD mortality was detected for men and women. Excess CVD mortality risks were observed among middle-aged women with no children (hazard ratio [HR] 2.43, 95% confidence interval [CI] 1.49, 3.96) and among middle-aged women and men with 8+ children (HR(women) 1.64, CI 1.02, 2.65; HR(men) 1.40, CI 1.01, 1.93) compared to those with two children. No clear pattern of association between cancer mortality and parity was apparent for men. Elderly women with 8+ children showed reduced mortality risks from reproductive cancers (HR 0.22, CI 0.05, 0.91). Similar parity-related mortality patterns were observed for men and women for deaths from CVD and other causes indicating biosocial pathways. The association between parity and cancer mortality differed by gender, age and type of cancer.