title: Vaginal birth after cesarean: neonatal outcomes and United States birth setting.
abstract: BACKGROUND
  Women who seek vaginal birth after cesarean delivery may find limited in-hospital options. Increasing numbers of women in the United States are delivering by vaginal birth after cesarean delivery out-of-hospital. Little is known about neonatal outcomes among those who deliver by vaginal birth after cesarean delivery in- vs out-of-hospital.
  
  
  OBJECTIVE
  The purpose of this study was to compare neonatal outcomes between women who deliver via vaginal birth after cesarean delivery in-hospital vs out-of-hospital (home and freestanding birth center).
  
  
  METHODS
  We conducted a retrospective cohort study using 2007-2010 linked United States birth and death records to compare singleton, term, vertex, nonanomolous, and liveborn neonates who delivered by vaginal birth after cesarean delivery in- or out-of-hospital. Descriptive statistics and multivariate regression analyses were conducted to estimate unadjusted, absolute, and relative birth-setting risk differences. Analyses were stratified by parity and history of vaginal birth. Sensitivity analyses that involved 3 transfer status scenarios were conducted.
  
  
  RESULTS
  Of women in the United States with a history of cesarean delivery (n=1,138,813), only a small proportion delivered by vaginal birth after cesarean delivery with the subsequent pregnancy (n=109,970; 9.65%). The proportion of home vaginal birth after cesarean delivery births increased from 1.78-2.45%. A pattern of increased neonatal morbidity was noted in unadjusted analysis (neonatal seizures, Apgar score <7 or <4, neonatal seizures), with higher morbidity noted in the out-of-hospital setting (neonatal seizures, 23 [0.02%] vs 6 [0.19%; P<.001]; Apgar score <7, 2859 [2.68%] vs 139 [4.42%; P<.001; Apgar score <4, 431 [0.4%] vs 23 [0.73; P=.01]). A similar, but nonsignificant, pattern of increased risk was observed for neonatal death and ventilator support among those neonates who were born in the out-of-hospital setting. Multivariate regression estimated that neonates who were born in an out-of-hospital setting had higher odds of poor outcomes (neonatal seizures [adjusted odds ratio, 8.53; 95% confidence interval, 2.87-25.4); Apgar score <7 [adjusted odds ratio, 1.62; 95% confidence interval, 1.35-1.96]; Apgar score <4 [adjusted odds ratio, 1.77; 95% confidence interval, 1.12-2.79]). Although the odds of neonatal death (adjusted odds ratio, 2.1; 95% confidence interval, 0.73-6.05; P=.18) and ventilator support (adjusted odds ratio, 1.36; 95% confidence interval, 0.75-2.46) appeared to be increased in out-of-hospital settings, findings did not reach statistical significance. Women birthing their second child by vaginal birth after cesarean delivery in out-of-hospital settings had higher odds of neonatal morbidity and death compared with women of higher parity. Women who had not birthed vaginally prior to out-of-hospital vaginal birth after cesarean delivery had higher odds of neonatal morbidity and mortality compared with women who had birthed vaginally prior to out-of-hospital vaginal birth after cesarean delivery. Sensitivity analyses generated distributions of plausible alternative estimates by outcome.
  
  
  CONCLUSIONS
  Fewer than 1 in 10 women in the United States with a previous cesarean delivery delivered by vaginal birth after cesarean delivery in any setting, and increasing proportions of these women delivered in an out-of-hospital setting. Adverse outcomes were more frequent for neonates who were born in an out-of-hospital setting, with risk concentrated among women birthing their second child and women without a history of vaginal birth. This information urgently signals the need to increase availability of in-hospital vaginal birth after cesarean delivery and suggests that there may be benefit associated with increasing options that support physiologic birth and may prevent primary cesarean delivery safely. Results may inform evidence-based recommendations for birthplace among women who seek vaginal birth after cesarean delivery.
authors.affiliation: Department of Nurse-Midwifery, School of Nursing, Oregon Health and Science University, Portland, OR. Electronic address: tildene@ohsu.edu.
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Tilden
authors.affiliation: Anthropology department, Oregon State University, Corvallis, OR.
authors.forename: Melissa
authors.initials: M
authors.lastname: Cheyney
authors.affiliation: Department of Obstetrics & Gynecology, Oregon Health and Science University, Portland, OR.
authors.forename: Jeanne-Marie
authors.initials: JM
authors.lastname: Guise
authors.affiliation: Department of Nurse-Midwifery, School of Nursing, Oregon Health and Science University, Portland, OR.
authors.forename: Cathy
authors.initials: C
authors.lastname: Emeis
authors.affiliation: Biostatistics & Design Program, Oregon Health and Science University, Portland, OR; Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, OR.
authors.forename: Jodi
authors.initials: J
authors.lastname: Lapidus
authors.affiliation: Department of Obstetrics & Gynecology, Oregon Health and Science University, Portland, OR.
authors.forename: Frances M
authors.initials: FM
authors.lastname: Biel
authors.affiliation: Biostatistics & Design Program, Oregon Health and Science University, Portland, OR.
authors.forename: Jack
authors.initials: J
authors.lastname: Wiedrick
authors.affiliation: Department of Obstetrics & Gynecology, Oregon Health and Science University, Portland, OR.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Snowden
mesh_terms: D000328:Adult; D001034:Apgar Score; D016550:Birthing Centers / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006700:Home Childbirth / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D011247:Pregnancy; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012640:Seizures / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D016064:Vaginal Birth after Cesarean / Q000706:statistics & numerical data*
keywords: VBAC; birth center; birth setting; cesarean; home birth; labor after cesarean; neonatal outcome; vaginal birth after cesarean