An incompetent cervix happens when weak cervical tissue causes or plays a part in a premature birth or the loss of a healthy pregnancy. An incompetent cervix also is called cervical insufficiency.
The cervix is the lower part of the uterus that opens to the vagina. Before pregnancy, it's usually closed and firm. As pregnancy goes on and you get ready to give birth, the cervix slowly changes. It softens, gets shorter and opens. If you have an incompetent cervix, it might begin to open too soon causing you to give birth too early.
An incompetent cervix can be a hard problem to diagnose and treat. If your cervix begins to open early, or if you've had cervical insufficiency in the past, you might benefit from treatment. This might include having a procedure done to close the cervix with strong sutures, called a cervical cerclage. You also may take medicine to help the incompetent cervix and have ultrasound exams to check how things are going.

The ovaries, fallopian tubes, uterus, cervix and vagina, also called the vaginal canal, make up the female reproductive system.
With an incompetent cervix, there may be no signs or symptoms during early pregnancy. Some women have mild discomfort or spotting before the diagnosis. Often, this occurs before 24 weeks of pregnancy.
Be on the lookout for:
Many women don't have a known risk factor. Risk factors for an incompetent cervix include:
An incompetent cervix may be risky for your pregnancy. Possible complications include:
You can't prevent an incompetent cervix. But there's a lot you can do to have a healthy, full-term pregnancy. For example:
If you've had an incompetent cervix during one pregnancy, you're at risk of premature birth or pregnancy loss in later pregnancies. If you're considering getting pregnant again, talk with your doctor to understand the risks and what you can do to promote a healthy pregnancy.