Risk factors

Many women don't have a known risk factor. Risk factors for cervical insufficiency include:

• Cervical trauma. Some surgical procedures used to treat cervical abnormalities associated with an abnormal Pap smear can result in cervical insufficiency. Other surgical procedures such as a D&C could also be associated with cervical insufficiency. Rarely, a cervical tear during a previous labor and delivery could be associated with an incompetent cervix.
• Race. Black women seem to have a higher risk of developing cervical insufficiency. It isn't clear why.
• Congenital conditions. Uterine abnormalities and genetic disorders affecting a fibrous type of protein that makes up your body's connective tissues (collagen) might cause an incompetent cervix. Exposure to diethylstilbestrol (DES), a synthetic form of the hormone estrogen, before birth also has been linked to cervical insufficiency.