Pathways from fertility history to later life health: Results from analyses of the English Longitudinal Study of Ageing

AbstractBACKGROUNDPrevious research shows associations between fertility histories and later life health. The childless, those with large families, and those with a young age at entry to parenthood generally have higher mortality and worse health than parents of two or three children. These associations are hypothesised to reflect a range of biosocial influences, but underlying mechanisms are poorly understood.OBJECTIVESTo identify pathways from fertility histories to later life health by examining mediation through health-related behaviours, social support and strain, and wealth. Additionally to examine mediation through allostatic load - an indicator of multisystem physical dysregulation, hypothesised to be an outcome of chronic stress.METHODSAssociations between fertility histories, mediators, and outcomes were analysed using path models. Data were drawn from the English Longitudinal Study of Ageing. Outcomes studied were a measure of allostatic load based on 9 biomarkers and self-reported long-term illness which limited activities.RESULTSEarly parenthood (CONCLUSIONIn England early parenthood and larger family size are associated with less wealth and poorer health behaviours and this accounts for much of the association with health. At least part of this operates through stress-related physiological dysfunction (allostatic load). 1. IntroductionRecognition of the importance of life-course influences on health and mortality at older ages has led to growing interest in the long-term consequences of reproductive pathways, particularly in the context of changing fertility patterns. Apart from the short-and long-term physiological influences of pregnancy, child birth, and lactation on women's health, broader biosocial mechanisms may link parenting trajectories with the later life health of both women and men. These include salutogenic influences of parenthood such as incentives to avoid health-damaging behaviours, role enhancement, greater community participation, and social support from children. However, parenthood also involves stresses of various kinds, including considerable economic costs, which may have health-damaging implications. In addition to the difficulty involved in unravelling effects of these countervailing influences, reproductive careers may be influenced by earlier health status and are associated with characteristics such as educational level and marital status, known to be related to health. Patterns of association observed and their interpretation may also depend on outcome measures used and age groups studied. Outcomes such as disability or death are usually sequelae of stresses, behaviours, and physiological changes accumulated over a long preceding period. Use of indicators of earlier pre-clinical changes in health may be helpful in elucidating the processes leading to these more distal outcomes. Allostatic load, conceptualised as multisystem physiological dysregulation arising from accumulated responses to multiple stressors, has been proposed as one such measure. In this paper we use path models within a structural equation-modelling framework to formally examine pathways from fertility histories to allostatic load and later life health, using longitudinal data from the English Longitudinal Survey of Ageing (ELSA). We investigate the extent to which associations are mediated by wealth, health-related behaviours, and social support and social strain in models controlling for socio-demographic characteristics and an indicator of respondents' health in childhood. …