What are the differences in pregnancy outcomes and complication rates after emergency cervical cerclage compared to ultrasound-indicated or history-indicated cervical cerclage? A systematic review and meta-analysis

Introduction: There is good evidence to support the use of ultrasound- (USS) or history- indicated cerclage to prevent preterm birth in certain at-risk populations [1]. However, the role of emergency cervical cerclage (ECC) in women with premature cervical dilatation and exposed membranes (CDEM) remains uncertain with a limited evidence-base. This systematic review forms part of a larger broad systematic review of ECC and the management of CDEM.

Methods: 5 databases were searched according to a prospectively published protocol (CRD42021286275). Studies were eligible if the population included women with CDEM and reported clinical outcomes. Searches identified 3165 Abstracts, 389 full texts were reviewed and 172 studies eligible for inclusion across 5 comparison groups. Primary outcome was pregnancy loss (miscarriage, neonatal death, termination, stillbirth), secondary outcomes included pregnancy prolongation, preterm birth, and maternal and neonatal outcomes. 23 eligible studies compared ECC with planned cerclage.

Results: Women receiving ECC were significantly more likely to experience pregnancy loss than women undergoing a planned cerclage (all pregnancies: RR 3.69 95% CI 2.62–5.20, 21 studies). Women receiving ECC were also more likely to deliver early (PTB <28/40 RR 4.84 95% CI 3.62–6.47, 4 studies), experience premature rupture of membranes (RR 2.57 95% CI 1.53–4.30, 6 studies) and develop chorioamnionitis (RR 3.02 95% CI 2.01–4.54, 9 studies).

Discussion: ECC may have a role in the management of women with CDEM however it is important that patients are counselled appropriately regarding the limitations of the evidence and that pregnancy outcomes and complication rates are not conflated with those from planned cerclage.