incompetent cervix

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Related to incompetent cervix: cerclage

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. 〈〉.


 [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.

incompetent cervix

Etymology: L, in, not, competentia, capable, cervix, neck
(in obstetrics) a condition characterized by painless dilation of the cervical os of the uterus before term without labor or contractions of the uterus. Miscarriage or premature delivery may result. Incompetent cervix is treated prophylactically by cerclage or another procedure in which the cervix is held closed by a surgically implanted suture.

incompetent cervix

 Cervical incompetence, see there.

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.
References in periodicals archive ?
My aim always has been to restore the incompetent cervix to normal anatomy and physiology to assure that pregnancy comes to term.
The soap star recently confirmed that her pregnancy had been problematic because doctors told her she had an incompetent cervix.
PLAINTIFF'S CLAIM Premature delivery was due to an incompetent cervix, which could have been treated with cerclage.
Cerclage obviously has no role in patients who do not have an incompetent cervix, or in such specific cases as the previable delivery of one dichorionic twin when a delayed-interval delivery of the second twin is desired.
The actress has been diagnosed with an incompetent cervix, which can cause premature birth or late miscarriage.
Do not offer progesterone to women at risk for preterm delivery who were not represented in the studies, such as women carrying multiples, women with previous medically indicated preterm deliveries, or anyone with an incompetent cervix.
She says: "Like all firsttime mums, I read up on pregnancy, and I learned about a rare condition called an incompetent cervix, possibly caused by having surgery.
The physician group that was caring for her considered the possibility of an incompetent cervix and requested--but never received--her prior medical records.
There were 10 pregnancy losses in the no-cerclage group that appeared consistent with a diagnosis of incompetent cervix; when taken together with the 29 women in the cerclage group presumed to have an incompetent cervix, the overall rate of cervical incompetence in the study was 4.