Uterus, contraction of the

Uterus, contraction of the: The tightening and shortening of the uterine muscles.

During labor, contractions accomplish two things: (1) they cause the cervix to thin and dilate (open); and (2) they help the baby to descend into the birth canal.

Uterine contractions also occur during the monthly menstrual cycle and are recognized as menstrual cramps.