A transabdominal cerclage (TAC) is a less common type of cerclage but has greater success rates than a traditional cerclage. This procedure involves placing a strong mersilene tape cerclage right at the level of the internal os, either through a c-section style incision or laprascopically. It can be placed before or during pregnancy. If during pregnancy, it is typically placed between 10 and 13 weeks. Once placed, the cerclage is considered permanent and all births need to be by caesarean section.
The advantage of this procedure is that it is placed right at the level of the internal os and has great success rates — typically around 98 percent if placed by a competent surgeon.