All About the Cervix

What is an incompetent cervix?

The cervix is designed to shorten and widen with your pre-labor contractions. If it does this without contractions it is said to be incompetent. If the cervix is unable to remain closed during pregnancy, this may cause preterm labor.

What is a cervical cerclage?

If a doctor decides your cervix is incompetent, he may suggest a cervical cerclage. This means stitches will be placed in your cervix to hold it closed. It is extremely rare; only about 1 percent of women have to have this procedure.

Is the cervix what dilates and gets measured?

"When a woman is checked in labor, it is the cervix that is evaluated as well as the station presenting part [usually the head]," says Dr. Nardone. "The cervix is evaluated for its thickness and dilatation. An example is that a cervical exam reveals the cervix to be 5 centimeters dilated and 75 percent effaced, with the head in 0 station. Normal labor progress occurs when there are regular contractions along with progressive cervical changes. If these don't occur, the OB provider has to evaluate the woman's labor and progress and determine what the problem is, such as poor quality contractions, a baby that is too big, a very tense patient, etc."

Can women have a cervix opening that is too small?

According to Dr. Nardone, the size of the cervical opening prior to or during pregnancy does not determine if a woman progresses in labor or not. "It is the quality of the contractions, the size of the baby, and the baby's presentation and station that allow the cervix to dilate," she says. "There are rare cases whereby a woman has a stenotic cervix, which means it is tightly shut and does not dilate at all. This can be due to scarring that could be the result of some type of infection, surgery, radiation treatment, or genetic anatomic abnormality. Again, this is a rare finding."

What is the mucus plug?

According to Dr. Oleg Bess, an OB-GYN from Olympia Medical Center in Los Angeles, the mucus plug is a collection of mucus just inside the cervix. "When the cervix begins to dilate, some of this mucus may come out," says Dr. Bess. "The mucus plug is an early indicator of labor."

Does the cervix come forward or down during pregnancy?

"The entire uterus prolapses after a vaginal delivery," says Dr. Bess. "Sometimes it is so low that the cervix can be felt near the outside of the vagina."