Cervical cerclage also known as a cervical stitch, is used for the treatment of cervical incompetence

Cervical incompetence

Cervical incompetence is a medical condition in which a pregnant woman's cervix begins to dilate and efface before her pregnancy has reached term. Internal os opening more than 1 cm is abnormal and cervical length less than 2 cm is considered diagnostic...

 (or insufficiency), a condition where the cervix has become slightly open and there is a risk of miscarriage

Miscarriage

Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving independently, generally defined in humans at prior to 20 weeks of gestation...

 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 12 to 14, 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, described in 1957 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 14 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 sometimes involves a permanent stitch around the cervix which will not be removed and therefore a Caesarean section
  Caesarean section
  A Caesarean section, is a surgical procedure in which one or more incisions are made through a mother's abdomen and uterus to deliver one or more babies, or, rarely, to remove a dead fetus...
  
   will be necessary to deliver the baby. The Shirodkar technique was first described by Dr. V. N. Shirodkar in Bombay in 1955. In 1963, Dr. Shirodkar traveled to NYC to perform the procedure at the New York Hospital of Special Surgery; the procedure was successful, and the baby lived to adulthood.
• An abdominal cerclage, the least common type, is permanent and involves stitching at the very top of the cervix, 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. However, a few doctors (namely Dr. Arthur Haney at the University of Chicago and Dr. George Davis at the University of Medicine and Dentistry of New Jersey) are pushing for the transabdominal cerclage to replace vaginal cerclages, due to perceived better outcomes and more pregnancies carried to term.

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, or up to two weeks. 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
• Cervical Dystocia with failure to dilate requiring Cesarean Section
• displacement of the cervix

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).