incompetent cervix

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Incompetent Cervix



A cervix (the structure at the bottom of the uterus) that is incompetent is abnormally weak, and therefore it can gradually widen during pregnancy. Left untreated, this can result in repeated pregnancy losses or premature delivery.


Incompetent cervix is the result of an anatomical abnormality. Normally, the cervix remains closed throughout pregnancy until labor begins. An incompetent cervix gradually opens due to the pressure from the developing fetus after about the 13th week of pregnancy. The cervix begins to thin out and widen without any contractions or labor. The membranes surrounding the fetus bulge down into the opening of the cervix until they break, resulting in the loss of the baby or a very premature delivery.

Causes and symptoms

Some factors that can contribute to the chance of a woman having an incompetent cervix include trauma to the cervix, physical abnormality of the cervix, or having been exposed to the drug diethylstilbestrol (DES) in the mother's womb. Some women have cervical incompetence for no obvious reason.


Incompetent cervix is suspected when a woman has three consecutive spontaneous pregnancy losses during the second trimester (the fourth, fifth and sixth months of the pregnancy). The likelihood of this happening by random chance is less than 1%. Spontaneous losses due to incompetent cervix account for 20-25% of all second trimester losses. A spontaneous second trimester pregnancy loss is different from a miscarriage, which usually happens during the first three months of pregnancy.
The physician can check for abnormalities in the cervix by performing a manual examination or by an ultrasound test. The physician can also check to see if the cervix is prematurely widened (dilated). Because incompetent cervix is only one of several potential causes for this, the patient's past history of pregnancy losses must also be considered when making the diagnosis.


Treatment for incompetent cervix is a surgical procedure called cervical cerclage. A stitch (suture) is used to tie the cervix shut to give it more support. It is most effective if it is performed somewhere between 14-16 weeks into the pregnancy. The stitch is removed near the end of pregnancy to allow for a normal birth.
Cervical cerclage can be performed under spinal, epidural, or general anesthesia. The patient will need to stay in the hospital for one or more days. The procedure to remove the suture is done without the need for anesthesia. The vagina is held open with an instrument called a speculum and the stitch is cut and removed. This may be slightly uncomfortable, but should not be painful.
Some possible risks of cerclage are premature rupture of the amniotic membranes, infection of the amniotic sac, and preterm labor. The risk of infection of the amniotic sac increases as the pregnancy progresses. For a cervix that is dilated 3 centimeters (cm), the risk is 30%.
After cerclage, a woman will be monitored for any preterm labor. The woman needs to consult her obstetrician immediately if there are any signs of contractions.
Cervical cerclage can not be performed if a woman is more than 4 cm dilated, if the fetus has already died in her uterus, or if her amniotic membranes are torn and her water has broken.


The success rate for cerclage correction of incompetent cervix is good. About 80-90% of the time women deliver healthy infants. The success rate is higher for cerclage done early in pregnancy.

Key terms

Diethylstilbestrol (DES) — DES is a drug given to women a generation ago to prevent miscarriage. At that time it was not known that female children born of women who had been given DES would show a higher rate for cervical and other reproductive abnormalities, as well as a rare form of vaginal cancer, when they reached reproductive age.
Effacement — The thinning out of the cervix that normally occurs along with dilation shortly before delivery.
Preterm labor — Labor before the thirty-seventh week of pregnancy.



Weiss, Robin. "Incompetent Cervix." The Mining Co. Guide to Pregnancy/Childbirth Page. March 1998. 〈〉.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


 [ser´viks] (pl. cer´vices) (L.)
1. neck.
2. the front portion of the neck.
3. cervix uteri.
Organs of the female reproductive system. From Applegate, 2000.
cervix den´tis neck of tooth.
incompetent cervix a cervix uteri that is abnormally prone to dilate before termination of the normal period of gestation, resulting in premature expulsion of the fetus. Predisposing factors include a previous traumatic delivery and previous dilatation and curettage. It may be corrected during pregnancy by cerclage using a band of fascia or a nonabsorbable ribbon of Mersilene to constrict the cervical os.
cervix u´teri (uterine cervix) the narrow lower end of the uterus between the isthmus and the opening of the uterus into the vagina.

Cervical cancer is surpassed only by lung cancer and breast cancer as a cause of female cancer deaths in the United States. Cervical erosion refers to ulceration of the surface epithelium of the cervix resulting from trauma (as in childbirth) or infection. Cervical lacerations are likely to occur during childbirth. Most small lacerations heal by themselves, but more extensive tears in the cervix may require surgical repair. Cervical polyps are fleshy growths that form on the cervix, causing bleeding, and can be removed surgically.
cervix vesi´cae urina´riae the lower, constricted part of the urinary bladder, near the opening of the urethra.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

incompetent cervix

 Cervical incompetence, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

incompetent cervix

A laxity or undue wideness of the inner mouth (internal os) of the outlet of the womb that commonly leads to repeated, painless miscarriages after the 16th week of pregnancy. The condition is treated by the insertion of a purse-string stitch of non-absorbable material which is removed shortly before term.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Despite several reported successes with cerclage in preventing mid-trimester pregnancy losses and preterm labour, there remains doubt as to the real value and place of cerclage in managing recurrent pregnancy loss due to incompetent cervix. In a meta analysis of randomized control trials by Drakeley et al (10), there was no statistical difference in pregnancy outcome between intervention and non intervention groups.
Rooney and Calhoun conclude that abortionists who merely point out the risk of infection or an incompetent cervix as potential abortion complications, without informing women how these may lead to future prematurity and its sequelae, may not escape liability.
My aim always has been to restore the incompetent cervix to normal anatomy and physiology to assure that pregnancy comes to term.
Complications requiring hospitalization during the pregnancies included incompetent cervix; threatened preterm labor; premature rupture of membranes (PROM); PPROM; hemolysis, elevated liver enzymes, and low platelet count (HELPP) syndrome; and placenta previa.
This test may be most useful in identifying women with an incompetent cervix, especially in the first two trimesters.
Many physicians suspect that multiple abortions lead to an increased incidence of future reproductive problems such as incompetent cervix which increases the chance of miscarriage.
An incompetent cervix will need to be monitored, possibly as an inpatient.
Placement of a suture around an incompetent cervix to prevent premature pregnancy loss was first described more than 50 years ago (1,2)--but the few randomized studies that have been published (all of them in the past decade) devote very little attention to technique.
EAR: Among women who present with a clinical picture of acute cervical insufficiency, also known as an "incompetent cervix," how common are infections?
Tests showed Katrina had an "incompetent cervix", where the small canal at the base of the womb shortens and dilates before the baby is due.
A careful history is essential to determine whether the patient experienced labor in the previous pregnancy loss, to distinguish incompetent cervix from premature labor.
After adjusting the results for possible confounding variables such as prior preterm delivery, cerclage, incompetent cervix, duration of intravenous tocolysis, and obesity, investigators calculated an odds ratio of 2.4 for preterm delivery in patients who were not maintained on oral tocolysis.