Insufficient cervix occur when the cervix begins to soften too early in a pregnancy. This could cause miscarriage or premature birth.
What is an Insufficient Cervix?
The cervix is the narrow lower end of the uterus that goes into the vagina.
- In a normal pregnancy, the cervix stays firm, long, and closed until late in the 3rd trimester.
- In the 3rd trimester, the cervix starts to soften, get shorter, and open up (dilate) as a woman's body prepares for labor.
An insufficient cervix may begin to dilate too early in pregnancy. If there is an insufficient cervix, the following problems are more likely to occur:
What Causes it?
No one knows for sure what causes an insufficient cervix, but these things may increase a woman's risk:
- Being pregnant with more than 1 baby (twins, triplets)
- Having an insufficient cervix in an earlier pregnancy
- Having a torn cervix from an earlier birth
- Having past miscarriages by the 4th month
- Having past first or second semester abortions
- Having a cervix that did not develop normally
- Having a cone biopsy or loop electrosurgical excision procedure (LEEP) on the cervix in the past due to an abnormal Pap smear
How do I Know I Have it?
Often, you will not have any signs or symptoms of an insufficient cervix unless you have a problem it might cause. That is how many women first find out about it.
If you have any of the risk factors for insufficient cervix:
- Your health care provider may do an ultrasound to look at your cervix when you are planning a pregnancy, or early in your pregnancy.
- You may have physical exam and ultrasounds more often during your pregnancy.
An insufficient cervix may cause these symptoms in the 2nd trimester:
- Abnormal spotting or bleeding
- Increasing pressure or cramps in the lower abdomen and pelvis
How is it Treated?
If there is a threat of premature birth, your provider may suggest bed rest. However, this has not been proven to prevent loss of pregnancy, and may result in complications for the mother.
Your provider may suggest you have a cerclage. This is a surgery to treat an insufficient cervix. During a cerclage:
- Your cervix will be stitched closed with a strong thread that will remain in place during the whole pregnancy.
- Your stitches will be removed near the end of the pregnancy, or sooner if labor begins early.
Cerclages work well for many women.
Sometimes, medicines such as progesterone are prescribed instead of a cerclage. These help in some cases.
Talk with your provider about your situation and treatment options.
Incompetent cervix; Weak cervix; Pregnancy - insufficient cervix; Premature labor - insufficient cervix; Preterm labor - insufficient cervix
Berghella V, Ludmir J, Owen J. Cervical insufficiency. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 35.
Buhimschi CS, Mesiano S, Muglia LJ. Pathogenesis of spontaneous preterm birth. In: Resnick R, Lockwood CJ, Moore TR, Greene MF, Copel JA, Silver RM, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 7.
Keyhan S, Muasher L, Muasher SJ. Spontaneous abortion and recurrent pregnancy loss: etiology, diagnosis, treatment. In: Lobo RA, Gershenson DM, Lentz GM, Valea FA, eds. Comprehensive Gynecology. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 16.
Review Date 10/5/2020
Updated by: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.