title: Association of the Duration of Active Pushing With Obstetric Outcomes.
abstract: OBJECTIVE
  To estimate the associations between the duration of active pushing during the second stage of labor and maternal and neonatal outcomes.
  
  
  METHODS
  We performed an observational study in which data were obtained by trained abstractors from maternal and neonatal charts of deliveries at 25 hospitals over a 3-year period. In this secondary analysis, women with no prior cesarean delivery who had a term, singleton, cephalic gestation and reached complete dilation were analyzed. The duration of pushing, defined as the time from initiation of pushing to either vaginal delivery or the decision to proceed with a cesarean delivery, was determined. The primary maternal outcome was cesarean delivery and the primary neonatal outcome was a composite that included: mechanical ventilation, proven sepsis, brachial plexus palsy, clavicular fracture, skull fracture, other fracture, seizures, hypoxic-ischemic encephalopathy, or death. Nulliparous and parous women were analyzed separately in univariable and then multivariable analyses.
  
  
  RESULTS
  A total of 53,285 women were analyzed. In both nulliparous and parous women, longer duration of pushing was associated with increased odds of both cesarean delivery and the neonatal adverse outcome composite. Nevertheless, even after 4 hours of pushing, approximately 78% of nulliparous women who continued with active pushing had a vaginal delivery and more than 97% did not have the composite adverse neonatal outcome. Similarly, after more than 2 hours of pushing, approximately 82% of parous women who continued active pushing delivered vaginally and more than 97% did not have the adverse neonatal outcome.
  
  
  CONCLUSIONS
  A longer duration of pushing is associated with an increased relative risk, but small absolute difference in risk, of neonatal complications. Approximately 78% of nulliparous women delivered vaginally even after 4 hours of pushing.
authors.affiliation: Departments of Obstetrics and Gynecology of Northwestern University, Chicago, Illinois, MetroHealth Medical Center-Case Western Reserve University, Cleveland, Ohio, Columbia University, New York, New York, the University of Utah Health Sciences Center, Salt Lake City, Utah, the University of Pittsburgh, Pittsburgh, Pennsylvania, The Ohio State University, Columbus, Ohio, the University of Alabama at Birmingham, Birmingham, Alabama, Wayne State University, Detroit, Michigan; Brown University, Providence, Rhode Island, the University of Texas Health Science Center at Houston-Children's Memorial Hermann Hospital, Houston, Texas, Oregon Health & Science University, Portland, Oregon; and the George Washington University Biostatistics Center, Washington, DC; and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland.
authors.forename: William A
authors.initials: WA
authors.lastname: Grobman
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bailit
authors.forename: Yinglei
authors.initials: Y
authors.lastname: Lai
authors.forename: Uma M
authors.initials: UM
authors.lastname: Reddy
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Mona
authors.initials: M
authors.lastname: Prasad
authors.forename: Alan T N
authors.initials: ATN
authors.lastname: Tita
authors.forename: George
authors.initials: G
authors.lastname: Saade
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Tolosa
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D000068104:Infant Health / Q000706:statistics & numerical data*; D007748:Labor Stage, Second; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012307:Risk Factors; D047929:Term Birth; D013997:Time Factors; D055815:Young Adult