title: Cervical cerclage for preterm birth prevention in twin gestation with short cervix: a retrospective cohort study.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Obstetrics and Gynecology, Saint Peter's University Hospital (SPUH), New Brunswick, NJ, USA.
authors.forename: C
authors.initials: C
authors.lastname: Houlihan
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: L C Y
authors.initials: LC
authors.lastname: Poon
authors.affiliation: Department of Obstetrics and Gynecology, Saint Peter's University Hospital (SPUH), New Brunswick, NJ, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ciarlo
authors.affiliation: Department of Obstetrics and Gynecology, Saint Peter's University Hospital (SPUH), New Brunswick, NJ, USA.
authors.forename: E
authors.initials: E
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Saint Peter's University Hospital (SPUH), New Brunswick, NJ, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Guzman
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D023802:Cerclage, Cervical / Q000379:methods*; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D016216:Ultrasonography, Prenatal / Q000379:methods
keywords: cerclage; cervical ultrasound; cervix; prematurity; twins