title: Secular trends in trial of labor and associated neonatal mortality and morbidity in the United States, 1995 to 2002.
abstract: OBJECTIVE
  A proportion of elective repeated cesarean sections where a trial of labor in a uterus with a previous scar was not attempted is on the increase. This study aimed to assess how reduced the use of trial of labor has impacted on neonatal outcomes in the United States.
  
  
  METHODS
  Pregnant women with one previous cesarean delivery and a singleton live birth of the index pregnancy were abstracted from the 1995 to 2002 birth registration data of the United States. Adjusted odds ratios for adverse neonatal outcomes of trial of labor were estimated by multiple logistic regression models, in overall study subjects and in the two periods with high and low rates of trial of labor.
  
  
  RESULTS
  A total of 1833407 eligible subjects were included in the analysis. Rate of trial of labor after one previous cesarean section dropped from 38.5% in 1995 to 15.0% in 2002. No significant change was observed in the patient population profile. Successful vaginal birth after cesarean delivery (VBAC) also declined from 76.6% in 1995 to 66.0% in 2002. A trial of labor after one previous cesarean section was correlated with increased risks of asphyxia-related neonatal death and neonatal morbidity. This risk was even more pronounced in low risk women and in the last study years with the lowest rate of trial of labor.
  
  
  CONCLUSIONS
  The reduced use of trial of labor after one cesarean delivery in recent years in the United States has actually resulted in increased risk of adverse neonatal outcomes associated with a trial of labor.
authors.affiliation: Department of Obstetrics and Gynecology, University of Ottawa, Faculty of Medicine, Ottawa Ontario K1H 8L6, Canada. swwen@ohri.ca
authors.forename: Shiwu
authors.initials: S
authors.lastname: Wen
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Guo
authors.forename: Rihua
authors.initials: R
authors.lastname: Xie
authors.forename: Jessica
authors.initials: J
authors.lastname: Dy
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
mesh_terms: D000328:Adult; D001238:Asphyxia Neonatorum / Q000453:epidemiology* / Q000209:etiology; D017604:Cesarean Section, Repeat; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D011247:Pregnancy; D014219:Trial of Labor; D014481:United States / Q000453:epidemiology; D016064:Vaginal Birth after Cesarean / Q000009:adverse effects* / Q000706:statistics & numerical data*; D055815:Young Adult