title: Factors associated with spontaneous preterm birth risk assessed by transvaginal ultrasound following cervical cerclage.
abstract: OBJECTIVE
  To determine the predictive value of various cervical length measurements postcerclage for the outcome of preterm birth following both elective and rescue cerclage.
  
  
  METHODS
  Over a five-year period, we identified 59 women who had a transvaginal cerclage inserted followed by serial cervical length measurement. Of these, 18 were elective cerclages placed at 14 weeks of gestation on the basis of a history of cervical insufficiency and 41 were rescue cerclages performed at gestations ranging from 17 to 23 weeks following a diagnosis of shortened cervix on ultrasound. The women were asymptomatic throughout.
  
  
  RESULTS
  There was a strong correlation between cervical length postcerclage and gestation at delivery. For both groups, preterm birth could be predicted by the total cervical length. In the rescue cerclage group, the change in cervical length was predictive, with positive changes associated with later gestation at delivery. The presence of funnelling was predictive of preterm birth in the elective cerclage group only.
  
  
  CONCLUSIONS
  Transvaginal cervical length measurement is useful in the prediction of preterm birth postcerclage placement. Serial cervical length measurement postcerclage may assist with timely addition of interventions such, progesterone and antenatal cortico steroids for fetal lung maturation.
authors.affiliation: Pregnancy Research Centre, Department of Perinatal Medicine, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.|Department of Obstetrics and Gynaecology, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Shirlene
authors.initials: S
authors.lastname: Sim
authors.affiliation: Pregnancy Research Centre, Department of Perinatal Medicine, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.|Department of Obstetrics and Gynaecology, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Fabricio
authors.initials: F
authors.lastname: Da Silva Costa
authors.affiliation: Department of Obstetrics, São Paulo Federal University (UNIFESP), São Paulo-SP, Brazil.
authors.forename: Edward
authors.initials: E
authors.lastname: Araujo Júnior
authors.affiliation: Pregnancy Research Centre, Department of Perinatal Medicine, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.|Department of Obstetrics and Gynaecology, The Royal Women's Hospital, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Penelope M
authors.initials: PM
authors.lastname: Sheehan
mesh_terms: D000328:Adult; D023802:Cerclage, Cervical; D054791:Cervical Length Measurement; D017558:Elective Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth / Q000000981:diagnostic imaging* / Q000517:prevention & control; D012189:Retrospective Studies; D016896:Treatment Outcome; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: cervical cerclage; cervical length; prediction; preterm birth; transvaginal ultrasound