title: Duration of the second stage of labor in multiparous women: maternal and neonatal outcomes.
abstract: OBJECTIVE
  This study was undertaken to examine perinatal outcomes associated with the second stage of labor in multiparous women.
  
  
  METHODS
  This is a retrospective cohort study of all term, cephalic, singleton births delivered by multiparous women between 1991 and 2001. Duration of the second stage of labor was stratified into hourly intervals: 0-1 hour, 1-2 hours, 2-3 hours, and 3 hours or longer. Perinatal outcomes were analyzed by using chi2 test and multivariable logistic regression models, by using P<.05 and 95% CI to indicate statistical significance.
  
  
  RESULTS
  Compared with women who delivered between the 0- and 2-hour interval, women with a second stage more than 3 hours had higher risks of operative vaginal deliveries (odds ratio = 13.27; 95% CI [9.38-18.8]), cesarean deliveries (odds ratio = 6.00; [4.06-8.86]), and maternal morbidity including third- or fourth-degree perineal lacerations, postpartum hemorrhage, and chorioamnionitis. Their neonates had higher risks of 5-minute Apgar score less than 7 (odds ratio = 3.63; 95% CI [1.77-7.43]), meconium stained amniotic fluid (odds ratio = 1.44; 95% CI [1.07-1.94]), admission to intensive care nursery (odds ratio = 2.08; 95% CI [1.15-3.77]), composite neonatal morbidity (odds ratio = 1.85; 95% CI [1.23-2.77]), and longer neonatal stay in the hospital (odds ratio = 1.67; 95% CI [1.11-2.51]).
  
  
  CONCLUSIONS
  Multiparous women with a second stage of 3 hours or greater are at increased risks for operative deliveries, peripartum morbidity, and undesirable neonatal outcomes. These outcomes should be considered in the management of multiparous women with a second stage of labor beyond 3 hours.
authors.affiliation: Division of Perinatal Medicine and Genetics, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, School of Medicine, San Francisco, CA, USA.
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Cheng
authors.forename: Linda M
authors.initials: LM
authors.lastname: Hopkins
authors.forename: Russell K
authors.initials: RK
authors.lastname: Laros
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Caughey
mesh_terms: D000328:Adult; D001034:Apgar Score; D002140:California / Q000453:epidemiology; D002585:Cesarean Section / Q000706:statistics & numerical data; D002821:Chorioamnionitis / Q000453:epidemiology; D015331:Cohort Studies; D004716:Endometritis / Q000453:epidemiology; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D007748:Labor Stage, Second; D007902:Length of Stay / Q000706:statistics & numerical data; D008470:Meconium; D015999:Multivariate Analysis; D010298:Parity; D010343:Patient Admission / Q000706:statistics & numerical data; D010502:Perineum / Q000293:injuries; D006473:Postpartum Hemorrhage / Q000453:epidemiology; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D014469:Umbilical Arteries / Q000737:chemistry