Fertility history and health in later life: a record linkage study in England and Wales.

Women born at different periods within the 20th century in England and Wales have followed varying fertility pathways with large changes in, for example, proportions having no children or only one child. Among the consequences of these changes may be effects on women's health later in life. Links between fertility histories and later health and mortality have been investigated in several studies, but in many of these socio-economic characteristics have not been allowed for, even though there are socio-economic differences in both fertility and mortality patterns and results are conflicting. Here we analyse associations between the fertility histories of women born 1911-1940 in England and Wales and their mortality and health status after age 50. We used data from the Office for National Statistics Longitudinal Study; a record linkage study of approximately 1% of the population initially based on those enumerated in the 1971 Census of England and Wales. We used survival analysis to investigate the effects of parity, short birth intervals, and timing of fertility on mortality from age 50 to the end of 2000, controlling for a range of relevant socio-demographic characteristics. For survivors to 1991, we additionally used logistic regression to model probability of having a limiting long-term illness in 1991. We found that nulliparous women and women with five or more children had significantly higher mortality than other women, and that in the oldest groups women with just one child also had raised mortality. Women who had been teenage mothers had higher mortality and higher odds of poor health than other parous women. Mothers with short birth intervals, including mothers of twins, also had elevated risks in some cohorts. Late childbearing (after age 39) was associated with lower mortality. Personal demographic history is an important factor to consider in analyses of health and mortality variations in later life. More research is needed to further elucidate causal pathways.