An incompetent cervix is a cervix that starts to painlessly open (efface and/or dilate) prematurely. The premature dilatation is not associated with discomfort, contractions, or infection. It may be caused by genetic factors or prior surgeries. If your mother took the drug DES (diethylstilbestrol) when she was pregnant with you, you may also be at risk for an incompetent cervix.

As pregnancy progresses and your unborn child grows and places more pressure on the cervix, without treatment an incompetent cervix may result in miscarriage. Women who have had problems with incompetent cervix in previous pregnancies are generally offered a prophylactic (or preventative) cerclage in the early second trimester. Cerclage is a minor surgical procedure to suture (stitch) the cervix closed, which may prevent premature cervical opening. There are several different methods of cerclage, including the Shirodkar, the McDonald, and abdominal cerclage. The most common type, the McDonald, is a temporary suture that is removed when labor begins.

A cerclage may also be placed if you have signs of preterm cervical shortening on physical exam or by ultrasound. This is called a rescue cerclageand may be less effective than one placed prophylactically. Since it is a controversial topic and a high-risk situation, consultation with a high-risk OB doctor should be made. Women at risk for preterm labor — including those with multiples' gestations, those with previous preterm labor, and those with cervical and uterine abnormalities — are generally followed more closely throughout pregnancy.

Women with an incompetent cervix may be regularly monitored using transvaginal ultrasound to detect any cervical changes. Finally, bed rest may be prescribed to keep weight off your uterus, and abstinence from sexual intercourse will probably be recommended.