An anterior lip, also known as an anterior cervical lip, is a term used in obstetrics to describe a specific condition during labor. It refers to a situation where a woman is almost fully dilated, but a portion of the cervix, usually the front part (anterior), remains slightly swollen and not fully pulled up and around the babys head. The anterior lip is the last part of the cervix to be taken up into the lower segment of the uterus.
During labor, the cervix does not open in a neat circle but is pulled open from the back to the front in an ellipse. The "os" (opening) is initially found tucked at the back of the vagina and opens forward as labor progresses. Almost every woman will experience an anterior lip at some point in labor, but its detection depends on whether and when a vaginal examination is done.
An anterior lip can potentially slow down a woman's progress from the first to the second stage of labor because the swelling will usually take time to reduce before the cervix can be fully pulled up and around the baby's head. However, in most cases, an anterior lip is a normal part of the birth process and does not require management.
