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Cervical length check in pregnancy: what the test shows

NNova editorial team · 5 min read

Cervical length measurement is a simple ultrasound test. For some pregnancies, it helps identify a higher risk of preterm birth so your care team can plan follow-up.

Why the cervix is measured

The cervix is the lower part of the uterus that helps keep a pregnancy in place until term. In the second trimester, its length may be measured to estimate the risk of preterm birth. Not every pregnancy needs this test, so ask your provider whether it makes sense for you.

How the test is done

  • It is most often done with a transvaginal ultrasound.
  • The test usually takes only a few minutes.
  • The provider looks at the length and shape of the cervix.
  • The result is interpreted together with your gestational age and pregnancy history.

What a short cervix may mean

A short cervix may lead to closer monitoring and a discussion of preventive options. These options depend on your history and the length measured. Your provider may talk with you about treatments such as vaginal progesterone or a cerclage, which is a stitch placed around the cervix.

Contact your provider right away or go to urgent care for cramping pain, pressure pushing downward, bleeding, or leaking fluid from the vagina. Call 911 if you have severe symptoms or heavy bleeding.

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General information only; it does not replace advice from your doctor or midwife.