Emergency cervical cerclage: predictors of success.

OBJECTIVE: To document predictors of success of emergency cervical cerclage. METHODS: This is a retrospective cohort study of 8 years at a university hospital. Emergency cerclage was defined as when the membranes were at or beyond the external os and was only performed where evidence of infection or labour were absent. Outcomes used were interval between cerclage and delivery, gestation at delivery; a 'good outcome' was defined as delivery after 32 weeks and healthy at discharge. Predictive factors for a successful pregnancy outcome were analysed using odds ratios (OR) with 95% confidence intervals. RESULTS: Forty-five emergency cerclages were performed, including 11 twin pregnancies. Twenty-one (47%) had a 'good outcome', including two twin pregnancies; 20 (44%) pregnancies reached 36 weeks. In 79.2% of 'poor outcomes' chorioamnionitis was found. Prolapsed membranes, advanced cervical dilatation, maternal symptoms and equivocal markers of infection were associated with a poor outcome, but not consistently enough to dictate management. CONCLUSIONS: Given the poor natural history of an open external os, emergency cerclage appears beneficial. That this might apply to twin pregnancies has implications for their management. Although success is indeed partly predictable, it can still be achieved even when there is advanced dilatation, prolapse, bleeding or discomfort.