title: Predicting factors for success of vaginal delivery in preterm induction with prostaglandin E2.
abstract: OBJECTIVE
  To evaluate the efficacy and safety of prostaglandin (PG) E2for preterm labor induction and to investigate the predictive factors for the success of vaginal delivery.
  
  
  METHODS
  A retrospective cohort study was performed in women (n=155) at 24+0 to 36+6 weeks of gestation who underwent induction of labor using a PGE2vaginal pessary (10 mg, Propess) from January 2009 to December 2015. Success rates of vaginal delivery according to gestational age at induction and incidence of intrapartum complications such as tachysystole and nonreassuring fetal heart rate were investigated. Multivariable logistic regression analysis was performed to evaluate the predictive factors for success of labor induction.
  
  
  RESULTS
  The vaginal delivery rate was 57% (n=89) and the rate of cesarean delivery after induction was 43% (n=66). According to gestational age, labor induction was successful in 16.7%, 50.0%, and 62.8% of patients at 24 to 31, 32 to 33, and 34 to 36 weeks, showing a stepwise increase (P=0.006). There were 18 cases (11%) of fetal distress, 9 cases (5.8%) of tachysystole, and 6 cases (3.8%) of massive postpartum bleeding (>1,000 mL). After adjusting for confounding factors, multiparity (odds ratio [OR], 8.47; 95% confidence interval [CI], 3.10 to 23.14), younger maternal age (OR, 0.84; 95% CI, 0.75 to 0.94), advanced gestational age at induction (OR, 1.06; 95% CI, 1.02 to 1.09), rupture of membranes (OR, 11.83; 95% CI, 3.55 to 39.40), and the Bishop score change after removal of PGE2(OR, 2.19; 95% CI, 1.0 to 4.8) were significant predictors of successful preterm vaginal delivery.
  
  
  CONCLUSIONS
  An understanding of the principal predictive factors of successful preterm labor induction, as well as the safety of PGE2, will provide useful information when clinicians consult with preterm pregnant women requiring premature delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yoo Min
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ji-Hee
authors.initials: JH
authors.lastname: Sung
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Suk-Joo
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Soo-Young
authors.identifier: 0000-0003-3002-0048
authors.initials: SY
authors.lastname: Oh
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheong-Rae
authors.initials: CR
authors.lastname: Roh
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jong-Hwa
authors.initials: JH
authors.lastname: Kim
keywords: Dinoprostone; Labor, induced; Premature birth; Vaginal delivery; Vaginal pessary