What is cerclage?

Sep 28, 2007 at 9:29 p.m. ET

A cerclage is a stitch placed in the cervix to provide additional support when its structural integrity is felt to be compromised. Dr David Barrere tells us more about the procedure and how it works.

Your question
What is a cerclage, and why is it done? What are the risks?

The expert answers
The most common situations in which a cerclage is utilized are 1) an incompetent cervix and 2) a shortened cervix.

An incompetent cervix is a "functionally weak" cervix that is unable to support the weight of a developing fetus. Often, this condition is diagnosed after a pregnancy loss between 20 and 22 weeks of gestation. Some possible causes include anatomy defects during development, surgery (especially elective abortions and cone biopsies) or cervical lacerations incurred during a previous delivery.

The average length of a cervix ranges from 2 to 5 centimeters. If an ultrasound determines the cervix to be less than 2 centimeters in length, a cerclage may be suggested to decrease the risk of miscarriage or premature delivery.

Two different methods of cerclage are available -- the Shirodkar and the MacDonald methods. Both work equally as well. The choice between the two is based entirely on the physician's training and experience with cerclage placement.

With any surgical procedure, there are potential risks. For cerclage placement, the risks include:

  1. Cervical stenosis or scarring that may preclude normal dilation during labor
  2. Infection
  3. Rupture of the fetal membranes (bag of water).