Also called cervical insufficiency, cervical incompetence is the inability of the cervix to remain shut during pregnancy. This means the cervix cannot bear pregnancy weight. Generally, the cervix is supposed to stay closed throughout the pregnancy. However, when the baby grows and becomes heavier, it puts pressure on the cervix. A weak or incompetent cervix is unable to bear this pressure and starts to dilate.

This incompetency could lead to premature birth and perhaps even death of the baby, thanks to the constricted pregnancy period. The problem usually comes to light somewhere between the second and third trimester. Cervical insufficiency is generally not the norm and only two out of 100 women face the issue.

Symptoms and Signs

Generally, the cervix widens without causing any pain or contractions. During the 15 to 20-week stage, some discomfort could be felt. Usually, the following symptoms and signs could indicate an incompetent cervix:

  • Pelvic pressure sensations
  • Backaches
  • Minor abdominal cramps
  • Mild vaginal bleeding
  • Vaginal discharge changes


The factors causing a cervix to go incompetent are:

  • History of cervical insufficiency with prior pregnancies
  • Prior cervical injury or surgery
  • History of dilation and curettage (D&C)
  • Heredity, or the presence of an oddly-shaped cervix right from birth
  • Anatomic cervical abnormalities
  • Use of anti-miscarriage drugs, such as DES drugs, when the now pregnant woman was in her mother’s womb. Such drugs can hurt a fetus’ reproductive tract.
  • Unusually short cervix


It’s not possible or there are no known methods to detect cervical incompetency before pregnancy or in the first trimester. As mentioned earlier, it’s detectable only during the second and third trimester. The diagnosis typically entails a physical exam, medical history lookup, and an ultrasound study. A pregnancy test is also done. Some other tests include a hysterosalpingography and radiography. During an ultrasound, the practitioner assesses the cervix length from the opening of the vagina to look for any signs of cervical shortening.


Once the incompetence is diagnosed, a surgical procedure known as cerclage is needed. The procedure is typically done after 12 weeks into pregnancy, when a miscarriage is least likely due to reasons other than cervical insufficiency. Generally, a cerclage is sutured in around the 15th week of pregnancy. But, the earlier the cerclage, the healthier and longer the pregnancy. However, a cerclage is not possible if there’s increased cervical irritation, the cervix has widened up by 4 cm or more, or there are membrane ruptures.  

A series of ultrasound treatments are carried out once every couple of weeks for monitoring the cervix. If the cervix looks weak or opens up, a cerclage is recommended. The cerclage is taken out prior to childbirth to make way for a vaginal delivery. But there are instances when the cerclage is left untouched and a caesarean section is carried out.     

Though the jury is still out on progesterone’s ability to tackle cervix incompetence risks, some doctors may recommend progesterone supplements if the pregnant woman has had several previous premature births.