Pregnancy outcomes after ultrasound- and physical examination-indicated cervical cerclage: a retrospective cohort study

OBJECTIVE: To compare pregnancy outcomes after emergency cervical cerclage according to indication: ultrasound-indicated versus physical examination-indicated cerclage. METHODS: This retrospective cohort study included singleton pregnancies that underwent emergency cerclage using the McDonald technique at 18-23.6 weeks of gestation at a single tertiary center between 2017 and 2023. Cases were classified according to indication: ultrasound-indicated cerclage (cervical length ≤ 25 mm with a closed cervix) or physical examination-indicated cerclage (painless cervical dilation ≥ 1 cm with visible membranes). The primary outcome was early preterm birth, defined as delivery before 34 weeks of gestation. Secondary outcomes included pregnancy prolongation following cerclage and other obstetric outcomes. RESULTS: Among 52 emergency cerclage cases, 39 patients underwent ultrasound-indicated cerclage and 13 underwent physical examination-indicated cerclage. Maternal characteristics and gestational age at the time of the procedure were similar between groups. Previous hysteroscopy was more common in the physical examination-indicated cerclage group (p = 0.035). Overall, 84.6% of patients (44/52) delivered after 34 weeks of gestation, with no significant difference in gestational age at delivery between groups (p = 0.886). Pregnancy prolongation did not differ significantly between groups (15.5 ± 4.2 vs. 13.3 ± 6.2 weeks; p = 0.168). In multivariable analysis, cerclage indication was not independently associated with early preterm birth, whereas pre-cerclage cervical length remained an independent predictor (aOR 0.73, p = 0.02). CONCLUSION: Emergency cervical cerclage was associated with substantial pregnancy prolongation. No statistically significant differences were observed between indications, and pre-cerclage cervical length was the only independent predictor of early preterm birth. These findings support, but do not confirm, a potential pathophysiologic continuum of cervical insufficiency.