Introduced in 1957, the McDonald cerclage is a surgery addressing cervical insufficiency or incompetence that involves placing a “purse string” suture around the cervix. The cervix is stitched with a 5 mm thick suture band. Performed typically under local anesthesia, the surgery must be done as early as possible in the pregnancy, before the cervix starts to efface or completely dilate. The vagina and vulva are prepared for the procedure with a soap solution, and the cervix exposed by placing a posterior retractor in the vagina.      

The cerclage is typically done during the 14th week of pregnancy, and removed around the 37th week (before labor and fetus delivery). Of the three cerclage procedures (including Shirodkar cerclage and abdominal cerclage), McDonald cerclage is more widespread and common.    

Pros and Cons

The main positive to the procedure is that it can be quickly performed, with little infection risks or blood loss. Removing a McDonald cerclage is also much easier, to facilitate a vaginal delivery.

However, unlike Shirodkar cerclage, the McDonald stitch cannot be placed high, thereby increasing the chances of damage to the bladder or rectum.