Birth Count May Echo in the Body's Clock, Finnish Study Finds

A Finnish study of 14,836 twin-derived women links both no children and high child counts (average ~6.8) to worse biological aging and higher mortality, while having about two to three children (and pregnancies at ages ~24–38) shows the best aging markers. Early births may also relate to aging, but effects largely fade after accounting for lifestyle factors. The findings are observational and not causal, and unmeasured variables may influence both reproductive history and health; researchers caution against using this to guide individual family planning.