The cervix is the entrance to the womb and plays an important part in the process of reproduction. A woman’s cervix goes through constant variations during her menstrual cycle. It changes position and shape throughout the month, every month. Once pregnancy has been achieved, however, the cervix goes through even more changes. These alterations can begin immediately upon conception and continue throughout the pregnancy until labor.
A pregnant cervix has more blood flowing through it, which can cause a change in color. A woman’s cervix is typically dark pink. Once she is pregnant, however, especially as the pregnancy progresses, her cervix may begin to turn dark blue.
The cervix is shaped like a thick tube, and begins as an organ that is tightly closed, and about one inch long. As the pregnancy progresses, and gets closer to term, the cervix will begin to change shape. It becomes shorter, and begins to efface, or get thinner. This change can take place over the last few months of pregnancy, or within an hour of labor.
In a pregnant woman, the cervix is always tightly closed, and blocked with a mucous plug, until the end of the pregnancy. Occasionally, a woman’s cervix will have difficulty remaining closed during pregnancy, which can cause infection or miscarriage. This condition is known as an incompetent cervix and can be remedied with a few stitches to hold the cervix closed until labor.
During the end of pregnancy, the cervix goes through the greatest changes of all. It changes length from approximately one inch to being completely effaced before the baby is born. It also dilates, or opens, during the end of pregnancy. Before and during labor, the cervix changes from a completely closed condition to fully open. When fully dilated, the cervical opening measures 10 centimeters. After childbirth, the cervix gradually returns to its previous shape and size. Typically, however, a cervix that has been through childbirth will not close as tightly thereafter.