Your uterus nourishes your growing baby for nine months. Once your baby is born, many of the blood vessels in your uterus break. The muscles of your uterus contract and squeeze them shut. Uterine ...

Uterine atony—also called atony of the uterus—occurs when the uterine muscles don't tighten after delivering a baby. If the muscles don't contract, the bleeding doesn't stop, causing postpartum ...