management

Last reviewed 01/2018

Cervical incompetence may be corrected by cervical encerclage - the placement of a circumferential suture in the supravaginal cervix at the level of the internal os.

A transvaginal approach is most common with either a Shirodkar or a McDonald suture inserted under general anaesthesia. The Shirodkar suture is placed circumferentially and submucosally whereas the Mcdonald suture is inserted without incising the epithelium, and surfaces at the four points of the compass. Each may be tied anteriorly or posteriorly.

Both are best inserted between 14-16 weeks gestation. This avoids 1st trimester abortions for which both methods are unhelpful and precedes cervical effacement and dilatation. Both are removed at 38 weeks or earlier if the patient goes into premature labour. The two methods are of comparable efficacy but the McDonald is easier to insert. Failure to remove the suture before labour may result in a cervical tear or uterine rupture.

A transabdominal approach is indicated if the cervix is congenitally short, amputated or scarred. The suture is placed above the cardinal and uterosacral ligaments, and the baby delivered by Caesarean section.