title: Elective cervical cerclage versus serial ultrasound surveillance of cervical length in a population at high risk for preterm delivery.
abstract: OBJECTIVE
  To compare pregnancy outcome for women at risk of preterm delivery undergoing elective cervical cerclage in the first trimester or serial transvaginal assessment of cervical length with cerclage only if indicated (control cases).
  
  
  METHODS
  A matched case control study.
  
  
  METHODS
  Prematurity clinic at two London teaching hospitals.
  
  
  METHODS
  Women at high risk for preterm delivery.
  
  
  METHODS
  Cases of elective cervical cerclage were matched for maternal age, ethnic group, previous cervical surgery, previous second trimester loss and early preterm delivery to women undergoing serial ultrasound surveillance of cervical length. Pregnancy outcome data was collected. Data was analysed using Fisher's exact, Mann-Whitney and Student's t-tests.
  
  
  METHODS
  Gestation at delivery, rate of delivery <24, 24-32 and 32-37 weeks gestation.
  
  
  RESULTS
  Thirty-nine cases of elective cervical cerclage were matched to control cases. Both groups were similar for maternal age, ethnic group, previous cervical surgery, previous second trimester loss and early preterm delivery. Cervical cerclage was performed in 14 (36%) of the control cases due to cervical changes. There was no significant difference in median gestation at delivery (266 days versus 260 days P=0.9), number delivering <24 weeks (15% versus 13% P=0.9), at 24-32 weeks (7.5% versus 15% P=0.6) and at 32-37 weeks (15% versus 13% P=0.9).
  
  
  CONCLUSIONS
  Serial transvaginal ultrasound surveillance of cervical length in women at high risk of preterm delivery appears to reduce cerclage rates without compromising pregnancy outcome. A large multicentered randomised trial is required to confirm these findings.
authors.affiliation: Imperial College London Research Group, Department of Obstetrics & Gynaecology, Institute of Reproductive and Development Biology, Queen Charlotte's & Chelsea Hospital, Hammersmith Campus, Imperial College School of Medicine, London, UK. k.groom@ic.ac.uk
authors.forename: Katie M
authors.initials: KM
authors.lastname: Groom
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Bennett
authors.forename: Monali
authors.initials: M
authors.lastname: Golara
authors.forename: Angeli
authors.initials: A
authors.lastname: Thalon
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Shennan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D023802:Cerclage, Cervical / Q000379:methods*; D020070:Cervical Ripening / Q000502:physiology; D017558:Elective Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D008991:Monitoring, Physiologic / Q000379:methods; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D011247:Pregnancy; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011336:Probability; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D016216:Ultrasonography, Prenatal / Q000379:methods*; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging* / Q000601:surgery*