Evolved birth physiology meets modern birth practice: Sustained effects of planned cesarean delivery on child hair cortisol in Brazil

Proceedings of the National Academy of Sciences, Volume 122, Issue 50, December 2025. <br/>SignificanceDuring labor, babies are exposed to mechanical forces and hormones that help prepare them for life outside the womb. Using data from a large sample of 4 to 7 y old children from Brazil, we found that those born by planned cesarean section had …