Incompetent Cervix

What is an incompetent cervix and what does it mean for the pregnancy if a woman has this diagnosis?

Simply put, an incompetent pregnancy is one that is unable to remain closed for a full term pregnancy. Abnormally weak, an incompetent cervix will gradually widen (dilate) and shrink (efface) typically during the second trimester of pregnancy as the uterus enlarges and becomes heavier. Undiagnosed, incompetent cervix often leads premature labor and/or miscarriage.

There are several possible causes for incompetent cervix. These include:

• Congenital abnormalities
• Hormonal changes such as occur during pregnancy
• prior cervical surgery (such as LEEP and conization)
• Trauma during another procedure (such as during dilation for D&C) or a prior traumatic delivery
• In Utero Exposure to DES (Diethylstilbestrol)
• No obvious reason

Unfortunately for many women, the first indication that they have an incompetent cervix is when preterm labor or a miscarriage occurs. With subsequent pregnancies these ladies may opt to have a cerclage, a surgical procedure during which the cervix is stitched closed, performed between about 14-16 weeks gestation. Depending on the woman’s situation, she may then be prescribed bed rest for the remainder of her pregnancy.

For some women, the incompetent cervix is not initially detected, but becomes suspect if a women has 3 consecutive pregnancy losses in the second trimester.  Pregnancy loss due to incompetent cervix occurs in about 20-25% of all second trimester pregnancy losses. An incompetent cervix can be detected via manual examination or by ultrasound.