Insufficient cervix
Incompetent cervix; Weak cervix; Pregnancy - insufficient cervix; Premature labor - insufficient cervix; Preterm labor - insufficient cervixInsufficient cervix occurs when the cervix begins to soften too early in a pregnancy. This could cause miscarriage or premature birth.
Miscarriage
A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. Pregnancy losses after the 20th week are called stillbirths. Mi...
Premature birth
A premature infant is a baby born before 37 full weeks of gestation (more than 3 weeks before the due date).
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:
- Miscarriage in the 2nd trimester
- Labor begins too early, before 37 weeks
Labor begins too early, before 37 weeks
Labor that begins before week 37 is called "preterm" or "premature. " About 1 out of every 10 babies born in the United States is born preterm. A pre...
Read Article Now Book Mark Article - Bag of water breaks before 37 weeks
Bag of water breaks before 37 weeks
Layers of tissue called the amniotic sac hold the fluid that surround a baby in the womb. In most cases, these membranes rupture during labor or wit...
Read Article Now Book Mark Article - A premature (early) delivery
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, or more)
- Having an insufficient cervix in an earlier pregnancy
- Having a torn cervix from an earlier birth
- Having previous miscarriages by the 4th month
- Having previous 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 measure the length of your cervix when you are planning a pregnancy, or early in your pregnancy.
- You may have physical exams 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.
Bed rest
Your health care provider may recommend you to stay in bed for a few days or weeks. This is called bed rest. Bed rest used to be recommended routine...
Depending on the length of the cervix, 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 to prevent preterm birth.
References
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: Lockwood CJ, Copel JA, Dugoff L, et al, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2023:chap 7.
Turocy J, Williams Z. Early and recurrent pregnancy loss: etiology, diagnosis, treatment. In: Gershenson DM, Lentz GM, Valea FA, Lobo RA, eds. Comprehensive Gynecology. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 16.
Review Date: 11/8/2024
Reviewed By: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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