Cervical cerclage

# Overview
Cervical cerclage (tracheloplasty), also known as a cervical stitch, is used for the treatment of cervical incompetence, a condition where the cervix has become slightly open and there is a risk of miscarriage because it may not remain closed throughout pregnancy. Usually this treatment would be done for a woman who had suffered one or more miscarriages in the past, in the second trimester of pregnancy.
The treatment consists of a strong suture being inserted into and around the cervix early in the pregnancy, usually between weeks 1214, and then removed towards the end of the pregnancy when the greatest risk of miscarriage has passed.

# Types
There are three types of cerclage:
- A McDonald cerclage is the most common, and is essentially a pursestring stitch used to cinch the cervix shut; the cervix stitching involves a band of suture at the upper part of the cervix while the lower part has already started to efface.  This cerclage is usually placed between 12 weeks and 16 weeks of pregnancy.  The stitch is generally removed around the 37th week of gestation.
- A Shirodkar cerclage is very similar, but the sutures pass through the walls of the cervix so they're not exposed. This type of cerclage is less common and technically more difficult than a McDonald, and is thought (though not proven) to reduce the risk of infection. The Shirodkar procedure involves a permanent stitch around the cervix because it will not be removed and therefore a Caesarean section will be necessary to deliver the baby. The Shirodkar technique was first used by Dr. Shirodkar in the United States in 1963; the procedure was successful, and the baby lived to adulthood.
- An abdominal cerclage, the least common type, is permanent and involves stitching inside the abdomen. This is usually only done if the cervix is too short to attempt a standard cerclage, or if a vaginal cerclage has failed or is not possible.

# Aftercare
After the cerclage has been placed, the patient will be observed for at least several hours (sometimes overnight) to ensure that she does not go into premature labor. The patient will then be allowed to return home, but will be instructed to remain in bed or avoid physical activity for two to three days. Follow-up appointments will usually take place so that her doctor can monitor the cervix and stitch and watch for signs of premature labor.

# Risks
While cerclage is generally a safe procedure, there are a number of potential complications that may arise during or after surgery. These include:
- risks associated with regional or general anesthesia
- premature labor
- premature rupture of membranes
- infection of the cervix
- infection of the amniotic sac (chorioamnionitis)
- cervical rupture (may occur if the stitch is not removed before onset of labor)
- injury to the cervix or bladder
- bleeding

# Normal results
The success rate for cervical cerclage is approximately 80-90% for elective cerclages, and 40-60% for emergent cerclages. A cerclage is considered successful if labor and delivery is delayed to at least 37 weeks (full term).

# Morbidity and Mortality Rates
Approximately 1-9% of women will experience premature labor after cerclage. The risk of chorioamnionitis is 1-7%, but increases to 30% if the cervix is dilated greater than 1.2 in (3 cm). The risks associated with premature delivery, however, are far greater. Babies born between 22 and 25 weeks of pregnancy are at significant risk of moderate to severe disabilities (46-56%) or death (approximately 10-30% survive at 22 weeks, increasing to 50% at 24 weeks, and 95% by 26 weeks).