Combined vaginal progesterone and cervical cerclage in the prevention of preterm birth: A systematic review and meta-analysis

Abstract

Background

Vaginal progesterone and cervical cerclage are both effective interventions for reducing preterm birth (PTB). It is currently unclear whether combined therapy offers superior effectiveness compared to single therapy.

Objective

To determine the efficacy of combining cervical cerclage and vaginal progesterone in the prevention of PTB.

Data sources

We searched Medline (Ovid), EMBASE (Ovid), PsycINFO (Ovid), CINAHL (EBSCOhost), Cochrane Library (Wiley) and Scopus (from their inception to 2020).

Study eligibility criteria

The review accepted randomized and pseudo-randomized control trials, non-randomized experimental control trials, and cohort studies. High risk patients (shortened cervical length <25mm or prior PTB) who were assigned cervical cerclage, vaginal progesterone, or both for the prevention of PTB were included. Only singleton pregnancies were assessed.

Study appraisal and synthesis methods

The primary outcome was birth <37 weeks. Secondary outcomes included birth <28, <32 and <34 weeks, gestational age (GA) at delivery, days between intervention and delivery, preterm premature rupture of membranes, neonatal mortality, neonatal intensive care unit admission, intubation and birthweight. Following title and full-text screening, eight papers were included in the final analysis. Risk of bias was assessed using the Cochrane Collaboration tool for assessing the risk of bias (ROBINS-I and RoB-2). Quality of evidence was assessed using the GRADE tool.

Results

Combined therapy was associated with lower risk of PTB <37 weeks compared to progesterone alone (RR 0.75, 95% CI 0.58, 0.96). Compared to cerclage only, combined therapy was associated with less PTB <32 weeks, decreased neonatal mortality, increased GA and a longer interval between intervention and delivery. Compared to progesterone alone, combined therapy was associated with less PTB <32 weeks, less PTB<28 weeks, increased GA, decreased neonatal mortality and decreased neonatal intensive care unit admissions.

Conclusions

Combined treatment of cervical cerclage and vaginal progesterone could potentially result in a greater reduction in PTB compared to single therapy. Further well-conducted and adequately powered randomized controlled trials are needed to assess these promising findings.