An incompetent cervix is a cervix that is too weak to stay closed during pregnancy. An incompetent cervix can cause miscarriage or premature labor with delivery of a premature infant.
The normal cervix begins to open after about nine months of pregnancy. It starts to open only in response to uterine contractions just before birth. But an incompetent cervix begins to open and thin out before contractions have begun and before a pregnancy has reached term. The cause is a weakness in the cervix. The weakened cervix opens because of growing pressure from the uterus as pregnancy progresses.
The main sign of an incompetent cervix is painless opening of the cervix without labor. It is most common between the third and seventh months of pregnancy. There may be vaginal spotting or bleeding. The amniotic membrane, also called the "bag of waters," then ruptures. This usually causes the loss of the unborn child. Without treatment, future pregnancies are likely to be affected as well.
Following are factors that increase the likelihood of an incompetent cervix: an abnormally formed cervix or uterus because of a birth defect, which may occur, for example, if a woman's mother took a drug called diethylstilbestrol, or DES, while she was pregnantdamage to the cervix, such as during a previous birthprevious surgery on the cervix, such as a cervical biopsy, a LEEP procedure or a dilatation and curettage, or D&C
If a woman has no history of an incompetent cervix, it usually cannot be prevented. After the diagnosis is made, treatment is available for future pregnancies.
An incompetent cervix is typically diagnosed when the woman begins to have symptoms. A physical exam by the healthcare provider will show the cervix beginning to shorten and dilate, or open. A pregnancy ultrasound, an X-ray test that uses sound waves, may also be done.
The long-term effects of an incompetent cervix are premature labor and miscarriage with each pregnancy. The emotional suffering after one or more miscarriages can be severe. Treatment is often successful in allowing full-term pregnancy and normal delivery.
An incompetent cervix is not contagious and poses risks only to the mother and baby.
A cervical cerclage can be used during pregnancy to prevent miscarriage in a woman with an incompetent cervix. A cerclage is a stitch inserted around the cervix to prevent it from opening too early. The procedure is usually done 14 to 16 weeks into the pregnancy.
The woman may be put on bed rest for a short period of time. The cerclage can be removed at the time of delivery, or it can be left in place if a cesarean birth is done.
Side effects of the surgical procedure to do the cerclage include bleeding, infection, and reaction to anesthesia.
Here is a list of the most common possible side effects of a cerclage: premature rupture of the membranes, or water breakinginfection of the uterus, fetal membranes, or fetuspremature laborinjury to the cervix
After a cerclage, the woman is kept on bed rest for 24 hours. She will be monitored for any uterine contractions, or labor. She will be advised to get plenty of rest each day and to decrease her physical activity for the remainder of her pregnancy. Vaginal intercourse should be avoided until after delivery. The stitch is most often removed just before the baby is due.
The woman will need to be followed closely throughout her pregnancy to check on the condition of the cervix. Prenatal visits will be more frequent than usual. The woman should tell her healthcare provider right away if she has any contractions or leaking of fluid from the vagina. Any other new or worsening symptoms should also be reported to the healthcare provider.
Introduction to Maternity and Pediatric Nursing, E Thompson, 1995.