title: Role of Cervical Length Measurement for Preterm Delivery Prediction in Women With Threatened Preterm Labor and Cervical Dilatation.
abstract: OBJECTIVE
  To compare the accuracy and cutoff points for cervical length for predicting preterm delivery in women with threatened preterm labor between those with a closed cervix and cervical dilatation.
  
  
  METHODS
  We conducted a retrospective cohort study of women with singleton pregnancies with threatened preterm labor before 34 weeks. The accuracy of cervical length for predicting preterm delivery was compared between women with cervical dilatation (0.5-3 cm) and those with a closed cervix. The predictive accuracy of cervical length for spontaneous preterm delivery was analyzed with several outcome-specific thresholds.
  
  
  RESULTS
  Overall, 1068 women with threatened preterm labor met the inclusion criteria; of them, 276 (25.8%) had cervical dilatation, and 792 (74.2%) had a closed cervix. The risk of preterm delivery before 37 weeks was significantly higher in the cervical dilatation group than the closed cervix group, as well as a shorter assessment-to-delivery interval of within 14 days (P = .001 and .004, respectively). On a multivariable analysis, cervical length was independently associated with the risk of preterm delivery in both groups. There was no significant difference between women with cervical dilatation and those with a closed cervix regarding the area under the receiver operating characteristic curves of cervical length for prediction of preterm delivery before 37 (0.674 versus 0.618; P = .18) and 34 (0.628 versus 0.640; P = .88) weeks and an assessment-to-delivery interval of 14 days (0.686 versus 0.660; P= .72). The negative predictive value of cervical length ranged from 77.4% to 95.7% depending on the different thresholds used.
  
  
  CONCLUSIONS
  Cervical length was significantly associated with the risk of preterm delivery in women presenting with threatened preterm labor and cervical dilatation of less than 3 cm. However, the predictive accuracy of cervical length as a single measure was relatively limited.
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel lirhir@gmail.com.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel lirhir@gmail.com.
authors.forename: Liran
authors.initials: L
authors.lastname: Hiersch
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Melamed
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Aviram
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Bardin
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yariv
authors.initials: Y
authors.lastname: Yogev
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Ashwal
mesh_terms: D000328:Adult; D054791:Cervical Length Measurement / Q000379:methods / Q000706:statistics & numerical data*; D002584:Cervix Uteri / Q000000981:diagnostic imaging; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: cervical dilatation; cervical length; obstetric ultrasound; preterm delivery; preterm labor