The effect of number of births on women's mortality: Systematic review of the evidence for women who have completed their childbearing

Abstract

Mortality in women who have completed their childbearing may increase with the number of births experienced because of maternal depletion or a trade-off between reproduction and mortality. We report a systematic review of the evidence on this association. We searched Medline, Embase, Popline, and the Science Citation Index for published and unpublished studies up to September 2003, and the book catalogues of relevant London libraries. Where necessary we also contacted authors for additional information. Mortality declined with increasing numbers of births in twelve historical cohorts, but in eight contemporary cohorts the highest mortality was seen in the nulliparous and in women with more than four births. All effects seen were small and there were few statistically significant results. Studies examining the relationship in other ways (such as by linear trends or by mean number of births by age at death) found inconsistent associations. We discuss methodological, social, and biological factors that may have affected these associations.

Exceptional longevity in female Rottweiler dogs is not encumbered by investment in reproduction

“…Since then, a freshly motivated field of investigators has reported mixed results in human populations, in some cases even showing a positive association between the number of offspring and longevity (reviewed by Helle et al 2005;Hurt et al 2006;Le Bourg 2007). This positive association may imply that successful reproduction, especially at advanced age, is a surrogate for increased fitness or quality of the mother (Doblhammer and Oeppen 2003;Gagnon et al 2009;Korpelainen 2000;McArdle et al 2006;Smith et al 2002;Yi and Vaupel 2004).…”

Twinning in humans: maternal heterogeneity in reproduction and survival

“…Hurt et al [20] found that in some selected cases, mortality actually declined with increasing births among 12 historical cohorts (populations unable to benefit from better healthcare available in modern societies), though results were inconsistent and not always significant.…”

Family systems and fertility : fertility behaviour in Europe from a network perspective

“…In addition, one alternative explanation could be a selection effect regarding the respondent who entered SHARE. Respondents with high fertility may face greater risk of dying earlier (Hurt, Ronsmans and Thomas 2006;Bulled and Sosis 2010), and it could thus be that especially older respondents with fewer children entered SHARE. On the contrary, recent research suggests no consistent pattern in the association between mortality and number of births among women who have completed their childbearing (Hurt, Ronsmans and Thomas 2006).…”

“…Respondents with high fertility may face greater risk of dying earlier (Hurt, Ronsmans and Thomas 2006;Bulled and Sosis 2010), and it could thus be that especially older respondents with fewer children entered SHARE. On the contrary, recent research suggests no consistent pattern in the association between mortality and number of births among women who have completed their childbearing (Hurt, Ronsmans and Thomas 2006). Moreover, life expectancy seems to vary according to regional socio-economic contexts that also influence fertility (Bulled and Sosis 2010).…”