Physiology, Pregnancy Contractions

Abstract

The uterus is a hollow organ that provides protective and nutritive support to the ovum from the moment it is fertilized until it grows into a well-developed fetus ready for parturition. Its middle muscular layer is called the myometrium, which is known for its rhythmic contractions which result in 'endometrial waves' in the nonpregnant uterus, Braxton Hicks contractions during pregnancy, and true labor towards the end of the third trimester. Labor contractions are painful, regular, and present with a change in cervical dilation and/or effacement.