title: Association between ultrasonographic parameters of Cesarean scar defect and outcome of early termination of pregnancy.
abstract: OBJECTIVE
  To determine whether Cesarean scar defect (CSD) parameters assessed by transvaginal sonography (TVS) might affect the outcome of early termination of pregnancy (TOP) with mifepristone-misoprostol.
  
  
  METHODS
  This was a retrospective review of 183 women with previous Cesarean delivery who received oral mifepristone and misoprostol for TOP. A successful TOP was defined by the absence of an intrauterine gestational sac, with no need for surgical intervention. CSD was diagnosed by TVS in the presence of a hypoechogenic indentation within the myometrium of the lower uterine segment at the site of a previous Cesarean incision. Women were analyzed in three subgroups according to size of defect (ratio of residual myometrial thickness over the defect to adjacent myometrial thickness < 30%, 30%-70% and > 70%).
  
  
  RESULTS
  Of the 183 women, 43 (23.5%) had failure of TOP. Fifty-nine (32.2%) had CSD detectable at TVS, and these women had a higher failure rate of TOP than did those without CSD (38.9% vs 16.1%; P = 0.001). CSD was associated significantly with failure of TOP (odds ratio, 3.32 (95% CI, 1.64-6.75)). The TOP failure rates in relation to defect size in the myometrial thickness ratio < 30%, 30%-70% and > 70% subgroups were 57.1%, 25.0% and 18.2%, respectively. There was a linear trend in failure rate across these ratios (Cochran-Armitage trend test; P = 0.015).
  
  
  CONCLUSIONS
  Women with CSD are at increased risk of failed TOP. Women with a defect in which the residual myometrial thickness was < 30% of the adjacent myometrial thickness tended to have a greater chance of failed TOP. CSD detected at TVS is of clinical relevance in counseling women with a history of Cesarean delivery who are considering TOP. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
authors: Department of Obstetrics and Gynecology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei, Taiwan.
authors: H-K
authors: HK
authors: Au
authors: Graduate Institute of Integration of Traditional Chinese Medicine with Western Nursing, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
authors: C-F
authors: CF
authors: Liu
authors: Department of Obstetrics and Gynecology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei, Taiwan.
authors: C-R
authors: CR
authors: Tzeng
authors: Department of Obstetrics and Gynecology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Obstetrics and Gynecology, Taipei Medical University Hospital, Taipei, Taiwan.
authors: L-W
authors: LW
authors: Chien
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000627:therapeutic use; D000028:Abortion, Induced / Q000009:adverse effects* / Q000379:methods; D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects*; D002921:Cicatrix / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D015735:Mifepristone / Q000627:therapeutic use; D016595:Misoprostol / Q000627:therapeutic use; D009215:Myometrium / Q000000981:diagnostic imaging / Q000473:pathology; D011183:Postoperative Complications / Q000209:etiology*; D011247:Pregnancy; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D016595:Misoprostol; D015735:Mifepristone
keywords: Cesarean delivery; Cesarean scar defect; medical abortion; mifepristone; misoprostol; transvaginal ultrasound