Signs and Symptoms of Incompetent Cervix

The cervix is a long, narrow passage at the lower end of the uterus. In a healthy pregnancy, the cervix will maintain its shape until late in the third trimester, at which point it will begin to soften, shorten, and dilate (open up) in preparation for birth. However, some pregnant women experience a condition called incompetent cervix (also known as insufficient cervix or cervical insufficiency).

This means that their cervix begins to shorten or dilate before the baby is ready to be born, putting the pregnancy at risk for miscarriage or premature birth. Medical professionals should know the risk factors and signs of incompetent cervix, and, if necessary, intervene to help the baby stay in the womb until term. Failure to provide the proper prenatal testing or treatments for incompetent cervix may result in serious birth injuries and constitute medical malpractice.

Signs and symptoms of incompetent cervix

Incompetent cervix is often asymptomatic (which is why it is so important for doctors to consider risk factors), although some women do experience mild symptoms. These signs typically appear between weeks 14 and 20 of pregnancy, and include:

  • Sensation of pelvic pressure
  • Backache
  • Abdominal cramps
  • Change in vaginal discharge (volume, color, or consistency)
  • Light vaginal bleeding/spotting
  • Braxton-Hicks-like contractions

Causes of incompetent cervix

Incompetent cervix may be caused by anything that can result in cervical weakness (i.e. the cervix is not strong enough to withstand the weight of the growing baby). Previous childbirths, surgical procedures, and individual anatomy may lead to incompetent cervix. Physicians must take a thorough history of the pregnant parent in order to identify risk factors for an incompetent cervix and premature birth.

Specifically, risk factors for incompetent cervix include:

  • Short cervical length
  • Prior miscarriage
  • Prior preterm delivery
  • Prior D&C procedure (dilation and curettage), which is a procedure used to clear the uterine lining after a miscarriage or pregnancy termination. It can also be used to diagnose and treat certain uterine conditions.
  • Prior loop electrosurgical excision procedure (LEEP) to remove abnormal/potentially cancerous cells from the cervix.
  • History of other surgical procedures involving the cervix
  • Diagnosis of incompetent cervix in a previous pregnancy
  • Twins or multiples pregnancy
  • Injury from a previous childbirth during which the cervix was torn (obstetric trauma)
  • Repeated or late-term abortion
  • Uterine abnormalities and anomalies
  • Exposure to the drug diethylstilbestrol (DES), a synthetic form of the hormone estrogen

Short cervix closely tied to cervical insufficiency

Short cervix (where the cervical tissue does not stay closed due to insufficient tissue length) is often synonymous with incompetent cervix. Although a certain degree of shortness can be caused by normal biological variance, it is usually the result of incompetent cervix. Management for these two conditions is very similar.

Diagnosing incompetent cervix

If any of the risk factors for an incompetent cervix are present, the physician should review the pregnant parent’s history and perform a physical exam and ultrasound tests to determine the length of the cervix. The diagnostic process typically involves taking:

  • Patient History:  An important indicator of an incompetent cervix is if the patient has had one or more miscarriages or extremely premature births (usually before week 28 of pregnancy) and no or minimal symptoms. It is also important for physicians to ask about other risk factors for incompetent cervix (see “Causes”)
  • Physical exam: During the second or third trimester, a pelvic exam to check for incompetent cervix can reveal the partial opening of the cervix (dilation) with shortening and thinning of the vaginal part of the cervix (effacement), which would indicate a weak cervix.
  • Tests: The physician should order serial transvaginal ultrasound studies (TVS) for anyone with risk factors for cervical incompetence. Transvaginal ultrasounds can help monitor the cervical length and determine if the cervix is shortening/opening.

Treatment for incompetent cervix

There are two important treatments for incompetent cervix – cervical cerclage and progesterone:

Cervical cerclage

cervical cerclage is a type of surgery that can help reinforce cervical muscle and prevent premature birth. During cerclage, a strong suture is sewn in and around the cervix, which helps it remain closed under the weight of the baby.  The surgery usually entails closing the cervix through the vagina (transvaginal cerclage).  Another approach involves performing the cerclage through an abdominal incision (transabdominal cerclage). Transabdominal cerclage is typically reserved for patients who are unable to have a transvaginal cerclage (e.g. those who have previously had a trachelectomy) or those in whom transvaginal cerclage has failed in the past.

According to the American College for Obstetricians and Gynecologists (ACOG), eligibility for cerclage can be based off of the following factors:

  • A history of incompetent cervix (typically, these patients would have a cerclage placed between approximately 13 and 14 weeks of pregnancy)
  • Physical examination findings (advanced dilation of the cervix without pain, and no signs of placental abruption or intraamniotic infection)
  • A history of premature birth combined with certain ultrasonographic findings

ACOG recommends that cerclages only be performed in the second trimester, before the fetus is viable (able to live outside the womb). This means the surgery should generally occur prior to 24 weeks of gestation. Cerclage is extremely effective in prolonging pregnancy in the face of cervical insufficiency.

A cerclage should be removed around 36-37 weeks of pregnancy, before the onset of labor. In the case of premature labor or the water breaking, it may need to be removed earlier. Cerclage is not recommended in patients with preterm premature rupture of membranes (PPROM), placental abruption, infection, or preterm labor.

Progesterone treatment

Progesterone is a pregnancy hormone that helps to prevent premature contractions and birth (it also benefits the growing baby in a variety of other ways). Patients with incompetent cervix should benefit from progesterone treatment. It can reduce the risk of premature birth by about one third. ACOG recommends providing progesterone only to patients with a history of spontaneous birth before 37 weeks of gestation. It can be given orally or via injection.

For a singleton pregnancy and a history of singleton premature birth, injections may begin between 16 and 20 weeks of pregnancy. Progesterone is not always recommended for multiple pregnancies; however, newer research on vaginal progesterone indicates that it may have some value in pregnancies with more than one baby.

cervical cerclage

The importance of preventing premature birth

Babies who are born prematurely are at higher risk of birth injuries and subsequent disabilities because of their underdeveloped organs and low birth weight. Conditions associated with premature birth include hypoxic-ischemic encephalopathy (HIE)cerebral palsy (CP)intellectual and developmental disabilities (I/DDs), hearing and vision impairments, and others.

Therefore, it is extremely important for doctors to do all they can to prevent premature birth in pregnancies involving incompetent cervix, and to minimize the risk of injury if premature birth is inevitable.

Legal Help

If your child has a birth injury due to a premature birth that could have been prevented, it is very important to choose a medical malpractice lawyer and firm that focus solely on birth injury cases.  ABC Law Centers: Birth Injury Lawyers (Reiter & Walsh, P.C.) has been exclusively helping children with birth injuries since 1997.

Our team handles cases all over the United States, including FTCA (Federal Tort Claims Act) cases involving military medical malpractice and federally-funded clinics.

Contact us to begin your free case evaluation. Our award-winning lawyers are available 24/7 to speak with you, and you pay nothing unless we win or favorably settle your case.

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Helpful resources

  1. Insufficient cervix: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved November 16, 2018, from
  2. Chandiramani, M., & Shennan, A. H. (2008). Cervical insufficiency: prediction, diagnosis and prevention. The Obstetrician & Gynaecologist10(2), 99-106.
  3. Incompetent Cervix : Weakened Cervix. (2015, December 02). Retrieved November 16, 2018, from
  4. Cervical insufficiency and short cervix. (n.d.). Retrieved November 16, 2018, from
  5. (n.d.). Retrieved November 16, 2018, from
  6. American College of Obstetricians and Gynecologists. (2014). ACOG practice bulletin No. 142: cerclage for the management of cervical insufficiency. Obstetrics and gynecology123(2 Pt 1), 372.
  7. (n.d.). Retrieved November 16, 2018, from
  8. (n.d.). Retrieved November 16, 2018, from
  9. Romero, R., Conde‐Agudelo, A., El‐Refaie, W., Rode, L., Brizot, M. L., Cetingoz, E., … & Perales, A. (2017). Vaginal progesterone decreases preterm birth and neonatal morbidity and mortality in women with a twin gestation and a short cervix: an updated meta‐analysis of individual patient data. Ultrasound in Obstetrics & Gynecology49(3), 303-314.