Fertility history and health in later life: A study among older women and men in the British Household Panel Survey Sanna Read and Emily Grundy Centre for Population Studies, London School of Hygiene and Tropical Medicine

Background (1): Previous studies have shown associations between fertility histories and later health and mortality (most studies based on mortality) but variation between populations and periods. These associations relevant to consideration of future resources and needs of older people as –they may have implications for future health status (as fertility patterns have changed) –They may moderate relationship between availability of children and needs for/use of different types of care Associations are hypothesised to reflect: Direct biological effects (Women) Selection effects Parental experiences –Social networks –Social support –Lifestyle and health-promoting behaviours –Roles

Previous findings : effects of fertility history on later life health Number of children: U-shaped pattern: childlessness and higher number of children related to higher mortality and poorer health The findings for health are mixed, the effects relatively small and inconsistent Background (2):

Previous findings: effects of fertility history on later life health Timing of births: Early childbearing (before age 20 or 23) related to poorer health outcomes The effect of late childbearing (after age 35 or 40) not clear; in some studies related to better health, some others to worse health or showed no relationship Short birth interval (under 18 months between the births) related to higher mortality, very few studies on the effect on health in later life Background (3):

Aim of the study Study the relationship between number of children and timing of births with health in later life –Women and men –Two age cohorts (aged and 60-79) –Multiple measures of health –Controlling for marital status, SES, smoking, and social support

Method A sample of 6175 women and men born between (aged 51-79) in the British Household Panel Survey Measures: –Health: limitation in functioning, self-rated health, psychiatric morbidity (GHQ >4), quality of life (CASP- 19) –Fertility history: number of children, birth before age 20 (women) or age 23 (men), birth after age 39, birth interval < 18 months –Background factors: age, marital status, education, tenure status, smoking, emotional support, co- residence with children (for parous only) Analysis: linear and logistic regressions

Summary of results Low (nulliparity or parity one) fertility was not associated with health in later life when background factors were controlled Higher fertility was associated with poorer health in later life, though –The effect was not significant for all measures of health –Controlling for background factors weakened the relationship –When timing of birth was taken into account the number of children was not associated with health in women Early childbearing was associated with increased risk of poorer heath in women and men Late childbearing was not associated with health Short birth interval (< 18 months) was related to poorer health only among older women

Odds ratios: final model for functional limitations Odds ratio

Odds ratios: final model for psychiatric morbidity Odds ratio

Limitations Small n → decreased power to detect significant differences Other possible confounding factors that were not controlled Reliability of the fertility data

Conclusions Confirms previous work suggesting that fertility histories have long-term health effects, both in women and men Effects on mental health in men and physical health in women The relationships between fertility histories and health in later life are partly explained by differences in marital status, SES, smoking and social support Questions for further research: –why has low fertility so little impact? –later birth cohorts with different fertility patterns? –the role of familial factors and interactions?