Scientists discover how the uterus knows when to push during childbirth

Childbirth depends not just on hormones, but on the uterus’s ability to sense physical force. Scientists found that pressure and stretch sensors in uterine muscles and surrounding nerves work together to trigger coordinated contractions. When these sensors are disrupted, contractions weaken and delivery slows. The discovery helps explain stalled labor—and could one day lead to better ways to manage childbirth.