Cervical cerclage and evidence-based medicine: if, how and when

Cervical cerclage has always been the main treatment option in cases of so-called cervical insufficiency, a condition that is notoriously associated with a high risk of second trimester abortion and/or preterm delivery. We can distinguish between a prophylactic cerclage, to be performed electively, usually at 13-16 weeks gestation, only when the woman has a history extremely suggestive for cervical incompetence (3 or more mid-trimester abortions or preterm deliveries) and a therapeutic cerclage. This last cerclage is recommended either for women who have ultrasonographic changes consistent with a short cervix or the presence of funneling after the 16-20 weeks gestation (urgent cerclage) and for women who present the asymptomatic dilation of the uterine cervix of at least 2 cm and/or a prolapse of the amniochorial membranes (emergent cerclage). So far there is still a lack of controlled and randomized trials that can unquestionably demonstrate the advantages of the cervical cerclage in comparison with a 'wait and see' aptitude. The cerclage can be performed either transvaginally, usually according to the McDonald technique, or transabdominally. This last approach is recommended when a transvaginal cerclage has to be avoided because of technical difficulties depending on the conditions of the cervix or when the pregnant woman has a history of one or more failed transvaginal cerclages. Interesting perspectives are currently offered by the laparoscopic cerclage, a method that has been effective and unexpectedly safe till now.