Cervical cerclage (Green-top Guideline No. 75). The purpose of this guideline is to review the literature and provide evidence-based guidance on the use of cerclage in women at risk of preterm birth and second trimester loss.
This guideline was developed as part of the regular programme of Green-top Guidelines, as outlined in our document Developing a Green-top Guideline: Guidance for developers (PDF), and prior to the emergence of COVID-19.
This is the first edition of this paper.
Cerclage remains one of the standard options performed prophylactic intervention in the care of women at risk of preterm birth and second trimester fetal loss and is used by most obstetricians, despite difficulties in identifying the population of women who would most benefit. The procedure, a stitch inserted into the cervix, was first performed in 1902 in women with a history of second trimester loss or spontaneous preterm birth suggestive of cervical insufficiency, with the aim of preventing recurrent loss.
Cervical insufficiency is an imprecise clinical diagnosis frequently applied to women with such a history, where it is assumed that the cervix is ‘weak’ and unable to remain closed during the pregnancy. Recent evidence suggests that, rather than being a dichotomous variable, cervical integrity is likely to be a continuum influenced by factors related not solely to the intrinsic structure of the cervix but also to processes driving premature effacement and dilatation. While cerclage may provide a degree of structural support to a ‘weak’ cervix, its role in maintaining the cervical length and the endocervical mucus plug as a mechanical barrier to ascending infection may be more important.
There is lack of consensus on the optimal cerclage technique, timing of suture placement, the role of amniocentesis before emergency cerclage insertion and optimal care following insertion. Complications are not well documented and often difficult to separate from risks inherent to the underlying condition. The purpose of this guideline is to review the literature and provide evidence-based guidance on the use of cerclage in women at risk of preterm birth and second trimester loss.
Please note that the information provided in this update will be considered for update by the RCOG Guidelines Committee 3 years after publication, with an intermediate assessment of the need to update 2 years after publication.
Developers’ declarations of interest
Available on request.