Primary, secondary, and tertiary preventions of preterm birth with cervical cerclage.

OBJECTIVE

To evaluate the efficacy of cerclage in preventing preterm birth according to indication.

STUDY DESIGN

Retrospective analysis of all women who underwent cerclage to prevent preterm birth in a university-affiliated medical-center (2007-2017). Multiple gestations were excluded. Cohort was divided to three subgroups according to cerclage indication: group A-primary prevention cerclage, performed during the first trimester, based on a history of cervical insufficiency; group B-secondary prevention cerclage, performed after sonographic visualization of asymptomatic cervical length shortening and previous preterm birth; and group C-tertiary prevention cerclage, performed at mid-trimester in women presenting with asymptomatic cervical dilatation. Primary outcome was gestational age at delivery. Secondary outcomes were maternal and neonatal complications.

RESULTS

During the study period 273 women underwent cervical cerclage: group A-215 (79%), group B-25 (9%), and group C-33 (12%). Patients in group C had significantly lower gravidity and parity. Gestational age at cerclage was highest in group C and lowest in group A (22 vs. 13 weeks p < 0.001). Median gestational age at delivery was 37 + 3 weeks in groups A and B and 34 + 3 in group C. This difference persisted after controlling for potential confounders (p  < 0.0001). Preterm birth prior to 34 weeks of gestation were 10.7% in group A, 16% in group B, and 33.33% in group C (p = 0.0021). Neonatal complications including: respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis, were clmore prevalent in group C.

CONCLUSION

Cerclage was shown to be an acceptable measure in cases of an anticipated increased risk of preterm birth with a low rate of procedure associated complications. However, the number-needed-to-treat cannot be determined from our data, because a control group was lacking.