title: Sequential cervical length screening in pregnancies after loop excision of the transformation zone conisation: a retrospective analysis.
abstract: OBJECTIVE
  To review our experience with a screening programme that included four sequential cervical length (CL) measurements from 16 to 22( ) weeks of gestation.
  
  
  METHODS
  Historical cohort study.
  
  
  METHODS
  Tertiary-care centre in a university hospital.
  
  
  METHODS
  There were 312 singleton pregnancies in 321 women with a previous large loop excision of the transformation zone (LLETZ), and 62 pregnancies after a second-trimester miscarriage in a previous pregnancy.
  
  
  METHODS
  The CL measurements were performed by transvaginal ultrasound at 16, 18, 20, and 22 completed weeks of gestation.
  
  
  METHODS
  Early preterm delivery before 34 completed weeks of gestation.
  
  
  RESULTS
  Early preterm delivery was found in 7.4%. The CL at 16 completed weeks of gestation was smaller in the LLETZ group (36 mm, interquartile range 30-40 mm) compared with the control group (38 mm, interquartile range 32-42 mm; P = 0.040). For the analysis of risk factors for early preterm delivery after LLETZ, only cases with a complete data set were included (n = 145). In a multivariate analysis, two parameters remained significantly predictive, with CL at 16 completed weeks of gestation being the most significant measure (P < 0.001, OR 0.90, 95% CI 0.83-0.98), followed by conception using IVF treatment (P = 0.031, OR 0.64, 95% CI 1.54-34.80).
  
  
  CONCLUSIONS
  Even as early as 16 weeks of gestation, women with early preterm delivery reveal a significantly lower CL than those without. Dynamics in the CL do not add to this information.
authors.affiliation: Department of Obstetrics and Gynaecology, Medical University of Vienna, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Pils
authors.forename: W
authors.initials: W
authors.lastname: Eppel
authors.forename: R
authors.initials: R
authors.lastname: Seemann
authors.forename: C
authors.initials: C
authors.lastname: Natter
authors.forename: J
authors.initials: J
authors.lastname: Ott
mesh_terms: D000022:Abortion, Spontaneous / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000000981:diagnostic imaging / Q000601:surgery*; D019092:Conization / Q000379:methods*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000000981:diagnostic imaging / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D008875:Middle Aged; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging / Q000209:etiology; D016017:Odds Ratio; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D047928:Premature Birth / Q000000981:diagnostic imaging / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000601:surgery*; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000601:surgery*
keywords: Cervical length; conisation; loop excision of the transformation zone; prediction; preterm delivery; risk factor