Cervical cerclage for preterm birth prevention in twin gestation with short cervix: a retrospective cohort study.

OBJECTIVE To determine if cervical cerclage reduces the rate of spontaneous early preterm birth in cases of dichorionic-diamniotic (DCDA) twin gestation with an ultrasound-detected short cervix. METHODS This was a retrospective cohort study of 40 consecutive DCDA twin gestations at Saint Peter's University Hospital from November 2006 to November 2014 in which cervical cerclage was performed for an ultrasound-determined cervical length of 1-24 mm at 16-24 weeks' gestation. The cases were matched with 40 controls without cerclage for cervical length and gestational age at cervical assessment. The primary outcome measure was spontaneous birth < 32 weeks. RESULTS There was no difference between the two groups in maternal age, body mass index (BMI), cigarette smoking, use of in-vitro fertilization (IVF), parity and prior spontaneous preterm birth. There were more Caucasian women among the controls compared with cases. In the cases, compared with controls, spontaneous delivery < 32 weeks was significantly less frequent (20.0% vs 50.0%; relative risk, 0.40 (95% CI, 0.20-0.80)). In the prediction of spontaneous delivery < 32 weeks, logistic regression analysis demonstrated that the risk was reduced with the insertion of cervical cerclage (odds ratio, 0.22 (95% CI, 0.058-0.835); P = 0.026), corrected for maternal age, BMI, racial origin, cigarette smoking, IVF, parity and previous preterm birth. CONCLUSION In DCDA twin gestation with a short cervix, treatment with cervical cerclage may reduce the rate of early preterm birth. The findings suggest the need for adequate randomized controlled trials on cerclage in twin gestations with a short cervix. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.