Association between number of children and mortality of mothers: results of a 37-year follow-up study

Abstract Purpose To examine the association between parity and long-term, all-cause mortality and mortality owing to specific causes in women. Methods This prospective population-based study included 40,454 mothers who gave birth in Western Jerusalem, Israel, to 125,842 children and were followed for an average of 37 years after the birth of their first child. Cox proportional hazards models were used to evaluate long-term total and specific-cause mortality of women by their parity. Results We found a U-shaped relationship between the number of offspring and risk of all-cause mortality in mothers. After adjustment for sociodemographic characteristics and maternal health and obstetric conditions, higher mortality rates were observed for mothers of 1 child (hazard ratio [HR], 1.18; 95% confidence interval [CI], 1.04–1.4), mothers of 5 to 9 children (HR, 1.21; 95% CI, 1.09–1.33), and mothers of 10 or more children (HR, 1.49; 95% CI, 1.12–1.99) compared with mothers of 2 to 4 children. Mortality risk from specific causes including coronary disease, circulatory disease, and cancer were increased for multiparous women. Conclusions In this long-term follow-up study, there was an association between number of children and mortality risk for mothers. These findings suggest that maternal pregnancies and postnatal characteristics as reflected by number of children may have consequences for long-term maternal health.