Reproductive history and mortality in late middle age among Norwegian men and women

Emily Grundy, London School of Hygiene and Tropical Medicine (LSHTM)
Øystein Kravdal, University of Oslo

There is growing recognition that reproductive patterns may have long-term health implications, although most evidence is restricted to women. The authors used register data to derive fertility histories for all Norwegian men and women born 1935-58. Discrete-time hazard modelling was used to analyse later-life mortality by aspects of reproductive history. 63,312 deaths were observed during 14.5 million person years of follow-up 1980-2003 when subjects were aged 45-68. Models included detailed information on educational qualifications and marital status. Results showed odds of death relative to those with two children were highest for the childless (women: OR 1.50, 95% CI 1.43, 1.57; men: 1.35, 1.30, 1.40) and next highest for those who had had only one child (women: 1.31; 1.26, 1.37; men: 1.20; 1.16, 1.24). Results for the parous showed a positive association between earlier parenthood and later mortality, a reverse association with late age at last birth, and an overall negative association between higher parity and mortality. The similarity of results for women and men suggests biosocial pathways underlying associations between reproductive history and health. The lack of any high parity disadvantage suggests that in the ‘family friendly’ Norwegian environment, the health benefits of having several children may outweigh the costs.