Last updated: 02/17/2009

Elective cervical cerclage is a minor surgical procedure that is generally performed between 12 and 14 weeks of pregnancy (at the beginning of the second trimester) before symptoms of premature labor begin. Emergent cerclages are those placed later...

in pregnancy when cervical changes have already begun.

The patient will usually receive regional (epidural or spinal) anesthesia during the procedure, although general anesthesia is sometimes used. Spinal anesthesia involves inserting a needle into a region between the vertebrae of the lower back and injecting numbing medications. An epidural is similar to a spinal except that a catheter is inserted so that numbing medications may be administered as needed. Some women experience a drop in blood pressure when a regional anesthetic is administered; this effect can be countered with fluids and/or medications.

While there are numerous techniques for performing cerclage, the McDonald and Shirodkar techniques are the most common. The McDonald cerclage involves stitching the cervix with a 0.2 in (5 mm) band of suture. The cerclage is placed high on the cervix when the lower part has already started to efface. The stitch is usually removed around week 37 of pregnancy. The classic Shirodkar procedure involves a permanent "purse-string" stitch around the cervix; because it will not be removed, a cesarean section will be necessary to deliver the baby. Most Shirodkar cerclages are now performed with a modified technique that allows the sutures to be later removed.

Some less common methods of cerclage include:

• Hefner (or Wurm) cerclage (usually reserved for later in pregnancy when there is little cervix to work with)
• abdominal cerclage (a permanent stitch performed through an abdominal incision instead of the vagina; reserved for when a vaginal cerclage has failed or is not possible)
• Lash cerclage (a permanent stitch performed before pregnancy because of trauma to the cervix or an anatomical abnormality)