title: Assessment of Cesarean hysterotomy scar before pregnancy and at 11-14 weeks of gestation: a prospective cohort study.
abstract: OBJECTIVE
  To compare the appearance and measurement of Cesarean hysterotomy scar before pregnancy and at 11-14 weeks in a subsequent pregnancy.
  
  
  METHODS
  This was a prospective cohort study of women aged 18-35 years who had one previous Cesarean delivery (CD) at ≥ 37 weeks. Women were examined with saline contrast sonohysterography 6-9 months after CD. A scar defect was defined as large if scar thickness was ≤ 2.5 mm. Women were followed up and those who became pregnant were examined by transvaginal ultrasound at 11-14 weeks. Scar thickness was measured and scars were classified subjectively as a scar with or without a large defect. A receiver-operating characteristics curve was constructed to determine the best cut-off value for scar thickness to define a large scar defect at the 11-14-week scan.
  
  
  RESULTS
  A total of 111 women with a previous CD were scanned in the non-pregnant state and at 11-14 weeks in a subsequent pregnancy. The best cut-off value for scar thickness to define a large scar defect at 11-14 weeks was 2.85 mm, which had 90% sensitivity (18/20), 97% specificity (88/91) and 95% accuracy (106/111). In the non-pregnant state, large scar defects were found in 18 (16%) women and all were confirmed at the 11-14-week scan. In addition, a large defect was found in three women at 11-14 weeks that was not identified in the non-pregnant state.
  
  
  CONCLUSIONS
  The appearance of the Cesarean hysterotomy scar was similar in the non-pregnant state and at 11-14 weeks in a subsequent pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
authors.affiliation: Department of Obstetrics and Gynecology, Skåne University Hospital Malmö, Lund University, Malmö, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Baranov
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: K Å
authors.initials: KÅ
authors.lastname: Salvesen
authors.affiliation: Department of Obstetrics and Gynecology, Skåne University Hospital Malmö, Lund University, Malmö, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Vikhareva
mesh_terms: D000293:Adolescent; D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects; D002921:Cicatrix / Q000000981:diagnostic imaging* / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D020883:Hysterotomy / Q000009:adverse effects*; D016742:Preconception Care; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D055815:Young Adult
keywords: 11-14-week scan; Cesarean delivery; non-pregnant women; saline contrast sonohysterography; scar defect; ultrasonography