Incompetent Cervix


There are no reliable tests that can be done before pregnancy to predict if you’ll have an incompetent cervix. Testing for an incompetent cervix can only be performed during pregnancy, presenting challenges, especially for first-time pregnancies.

To make this diagnosis, your doctor or care team may inquire about your symptoms and medical history. It’s important to disclose any history of pregnancy loss in the second trimester or a previous preterm delivery, as well as any cervical procedures you may have undergone.

A diagnosis of an incompetent cervix may be considered if you exhibit:

  • A history of painless cervical dilation and second-trimester delivery in a past pregnancy.
  • Advanced cervical dilation and effacement before the 24th week of pregnancy, where effacement indicates thinning and softening of the cervix. These changes can occur without painful contractions and may coincide with vaginal bleeding, infection, or ruptured membranes (when the water breaks).

The second-trimester diagnosis of an incompetent cervix may involve:

  • Pelvic Exam: The doctor checks the cervix to determine if the amniotic sac can be felt through the opening. If the sac’s wall is in the cervical canal or vagina, known as prolapsed fetal membranes, it indicates the cervix has started to open. The doctor may also monitor contractions if necessary.
  • Lab Tests: In cases of prolapsed fetal membranes, additional tests may be required to rule out infection. This could involve taking a sample of amniotic fluid through a procedure called amniocentesis, which checks for infection in the amniotic sac and fluid.
  • Transvaginal Ultrasound: This involves placing a thin, wand like device (transducer) inside the vagina to generate images on a screen. It helps assess the length of the cervix and identifies any protruding tissues.

There are currently no reliable pre-pregnancy tests to predict the likelihood of an incompetent cervix. However, certain tests conducted before pregnancy, such as ultrasound or Magnetic Resonance Imaging (MRI), may help identify congenital uterine problems that could contribute to an incompetent cervix.


Various treatment options and management strategies for an incompetent cervix include:

  • Progesterone supplementation: If you possess a short cervix without a history of preterm birth, the use of vaginal progesterone may reduce the risk of premature delivery. This medication is available in the form of a gel or a suppository, administered daily into the vagina.
  • Repeated ultrasounds: Individuals with a history of early premature birth or factors increasing the risk of an incompetent cervix may undergo frequent ultrasound monitoring of cervix length. This surveillance typically occurs every two weeks from week 16 through week 24 of pregnancy. If signs of cervical opening or shortening emerge, a cervical cerclage may be recommended.
  • Cervical cerclage: This procedure involves tightly stitching the cervix closed. The stitches are typically removed during the last month of pregnancy or just before delivery. Cervical cerclage may be considered if the woman is less than 24 weeks pregnant, has a history of early births, and ultrasound indicates cervical changes. In some cases, cervical cerclage is performed preventively before any signs of cervical opening, known as prophylactic cervical cerclage. This is often done before 14 weeks of pregnancy. However, it is not recommended for everyone at risk of premature birth, especially for those pregnant with twins or more. Discussion with the doctor about the risks and benefits of cervical cerclage is crucial.
  • Pessary: A device called a pessary is inserted into the vagina to support and hold the uterus in place, potentially alleviating pressure on the cervix. However, more research is needed to determine the efficacy of a pessary in treating an incompetent cervix.