title: Serial Change in Cervical Length for the Prediction of Emergency Cesarean Section in Placenta Previa.
abstract: OBJECTIVE
  To evaluate whether serial change in cervical length (CL) over time can be a predictor for emergency cesarean section (CS) in patients with placenta previa.
  
  
  METHODS
  This was a retrospective cohort study of patients with placenta previa between January 2010 and November 2014. All women were offered serial measurement of CL by transvaginal ultrasound at 19 to 23 weeks (CL1), 24 to 28 weeks (CL2), 29 to 31 weeks (CL3), and 32 to 34 weeks (CL4). We compared clinical characteristics, serial change in CL, and outcomes between the emergency CS group (case group) and elective CS group (control group). The predictive value of change in CL for emergency CS was evaluated.
  
  
  RESULTS
  A total of 93 women were evaluated; 31 had emergency CS due to massive vaginal bleeding. CL tended to decrease with advancing gestational age in each group. Until 29-31 weeks, CL showed no significant differences between the two groups, but after that, CL in the emergency CS group decreased abruptly, even though CL in the elective CS group continued to gradually decrease. On multivariate analysis to determine risk factors, only admissions for bleeding (odds ratio, 34.710; 95% CI, 5.239-229.973) and change in CL (odds ratio, 3.522; 95% CI, 1.210-10.253) were significantly associated with emergency CS. Analysis of the receiver operating characteristic curve showed that change in CL could be the predictor of emergency CS (area under the curve 0.734, p < 0.001), with optimal cutoff for predicting emergency cesarean delivery of 6.0 mm.
  
  
  CONCLUSIONS
  Previous admission for vaginal bleeding and change in CL are independent predictors of emergency CS in placenta previa. Women with change in CL more than 6 mm between the second and third trimester are at high risk of emergency CS in placenta previa. Single measurements of short CL at the second or third trimester do not seem to predict emergency CS.
authors: Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Jae Eun
authors: JE
authors: Shin
authors: Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Jong Chul
authors: JC
authors: Shin
authors: Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Young
authors: Y
authors: Lee
authors: Department of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Sa Jin
authors: SJ
authors: Kim
mesh_terms: D000328:Adult; D019540:Area Under Curve; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000503:physiopathology*; D002585:Cesarean Section; D005260:Female; D005865:Gestational Age; D006801:Humans; D016017:Odds Ratio; D010923:Placenta Previa / Q000503:physiopathology / Q000601:surgery*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D016216:Ultrasonography, Prenatal; D014592:Uterine Hemorrhage / Q000209:etiology