Introduction
Aging-related diseases and premature death pose significant threats to
health[1-4]. Given the global impact of these
issues, it is crucial to comprehend the influence of modifiable risk
factors. Women childbirth is a fundamental aspect of human behavior,
playing a vital role in maintaining women’s health. Current studies on
childbirth and women’s health predominantly focus on the health effects
of the number of births, leading to two contrasting viewpoints. Some
studies propose that childbirth may reduce the risk of breast cancer,
uterine cancer and ovarian cancer by decreasing exposure to progesterone
and estrogen[5,6], which is believed to counteract
negative physiological changes that accumulate with an increasing number
of births, potentially delaying the aging
process[7]. Conversely, other studies argue that
childbirth consumes a significant portion of resources through
reproduction, diverting resources away from the maintenance and repair
of somatic tissues, consequently accelerating the aging process.
Therefore, it remains largely uncertain whether and how the number of
childbirths influences women’s health.
Further, results from observational studies regarding the potential link
between number of births and women’s risk of mortality are
inconsistent[8-12]. Some studies found that there
is a negative association between number of birth and women’s risk of
mortality, whereas other studies showed that such association is
U-shape[13,14]. There are even studies suggesting
a non-significant association[15]. Despite the
relatively large sample sizes in some studies, they often failed to
account for potential confounding factors such as economic, behavioral,
and dietary variables[13,14,16]. At the
sociological level, raising children can avoid unhealthy behaviors by
improving their lifestyle and often involves more social
participation[17,18], but it may also increase
women’s stress, related depression risks, and significant economic costs[19-23]. Therefore, there is a need for a
comprehensive study with a sufficiently large sample size that considers
a wide range of confounding variables.
To fill this knowledge gap, this study utilize data from the UK Biobank
(UKB) to assess the association between the number of live births and
women’s aging, premature all-cause mortality, and life expectancy.
Meanwhile, extensive confounding including socioeconomic factors,
lifestyle factors and biological factors were adjusted for accurate
evaluation. This study may add insights into relationships between
childbirth and women’s aging, premature all-cause mortality, and life
expectancy for the first time, for clinical and public health reference,
being useful for future production interventions.