title: The effect of therapeutic McDonald cerclage on cervical length as assessed by transvaginal ultrasonography.
abstract: OBJECTIVE
  Our goal was to study the effect of therapeutic McDonald cerclage on cervical length with the use of transvaginal ultrasonography.
  
  
  METHODS
  Cervical length was measured serially in singleton pregnancies in which there were doubts regarding cervical competence. When shortening of the cervix was substantial before 27 weeks' gestation a McDonald cerclage was applied. Wilcoxon signed rank test was used, and 1-tailed P <.05 was considered significant.
  
  
  RESULTS
  In the 34 pregnancies studied, the mean cervical length measured at a mean gestational age of 14 weeks had decreased significantly (P <.0001) from 42 mm (95% confidence interval 38-47) to 21 mm (95% confidence interval 19-23) at a mean gestational age of 20 weeks 5 days, when a cerclage was applied. After the cerclage the mean cervical length increased significantly (P <.0001) to 34 mm (95% confidence interval 30-38) at a mean gestational age of 22 weeks 1 day (95% confidence interval 21 weeks 1 day-23 weeks 2 days).
  
  
  CONCLUSIONS
  Therapeutic McDonald cerclage results in a longer cervical length as measured by transvaginal ultrasonography.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: S M
authors.initials: SM
authors.lastname: Althuisius
authors.forename: G A
authors.initials: GA
authors.lastname: Dekker
authors.forename: H P
authors.initials: HP
authors.lastname: van Geijn
authors.forename: P
authors.initials: P
authors.lastname: Hummel
mesh_terms: D000328:Adult; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D014463:Ultrasonography; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging / Q000601:surgery*; D014621:Vagina