Fertility History, Children's Gender, and Post-Reproductive Survival in a Longevous Population

Area of Science:

• Demography
• Gerontology
• Reproductive Biology

Background:

• Investigating the link between maternal fertility history and post-reproductive survival is crucial for understanding longevity.
• Previous research has explored the influence of reproductive patterns on lifespan, with varying results.
• The unique demographic context of Villagrande Strisaili, Sardinia, offers a valuable setting for longevity studies.

Purpose of the Study:

• To analyze the relationship between mothers' fertility patterns and their post-reproductive lifespan.
• To determine if factors like age at last birth and offspring sex ratio impact maternal mortality risk.

Main Methods:

• Utilized data from 539 mothers in Villagrande Strisaili, Sardinia, who survived past age 50.
• Employed statistical analysis to adjust for confounders such as birth cohort and spouse survival.
• Examined the association between age at childbirth, offspring sex ratio, and post-reproductive mortality risk.

Main Results:

• Later average age at childbirth was associated with a 2.9% reduced mortality risk per year.
• A higher ratio of male offspring correlated with decreased maternal mortality.
• Mothers delivering sons after age 35 showed significantly longer survival (p=0.005), a finding not observed for daughters.

Conclusions:

• Fertility patterns, including age at last birth and sex ratio of offspring, are linked to post-reproductive survival in women.
• The observed association between later childbirth of sons and reduced mortality may be influenced by sociocultural and economic factors.
• Further research is needed to elucidate the complex interplay between reproductive history, offspring characteristics, and female longevity.