When labor begins, the uterus must coordinate rhythmic, well-timed contractions to deliver the baby safely. While hormones such as progesterone and oxytocin are key contributors to that process, scientists have long suspected that physical forces—in this case, the stretching and pressure that accompany pregnancy and delivery—also play a role.

Now, a new study from Scripps Research published in Science, reveals how the uterus senses and responds to those forces at a molecular level. The findings could help scientists better understand the biological roots of conditions such as stalled labor and preterm birth, guiding future efforts to develop treatments that improve maternal care.

“As the fetus grows, the uterus expands dramatically, and those physical forces reach their peak during delivery,” says senior author Ardem Patapoutian, a Howard Hughes Medical Institute Investigator and the Presidential Endowed Chair in Neurobiology at Scripps Research.