Cervical cerclage in the prevention of preterm birth.

Cervical cerclage has been used in the management of cervical insufficiency for several decades, yet the indications are uncertain and benefits marginal. It remains a controversial intervention. The diagnosis of cervical insufficiency is traditionally based on a history of recurrent second trimester miscarriages, or very preterm delivery whereby the cervix is unable to retain the pregnancy until term. Cervical cerclage has been the subject of many observational and randomised controlled trials. This article reviews the literature regarding the effectiveness of elective or emergency transvaginal cerclage and transabdominal cerclage.