title: Timing of elective repeat cesarean delivery at term and neonatal outcomes.
abstract: BACKGROUND
  Because of increased rates of respiratory complications, elective cesarean delivery is discouraged before 39 weeks of gestation unless there is evidence of fetal lung maturity. We assessed associations between elective cesarean delivery at term (37 weeks of gestation or longer) but before 39 weeks of gestation and neonatal outcomes.
  
  
  METHODS
  We studied a cohort of consecutive patients undergoing repeat cesarean sections performed at 19 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network from 1999 through 2002. Women with viable singleton pregnancies delivered electively (i.e., before the onset of labor and without any recognized indications for delivery before 39 weeks of gestation) were included. The primary outcome was the composite of neonatal death and any of several adverse events, including respiratory complications, treated hypoglycemia, newborn sepsis, and admission to the neonatal intensive care unit (ICU).
  
  
  RESULTS
  Of 24,077 repeat cesarean deliveries at term, 13,258 were performed electively; of these, 35.8% were performed before 39 completed weeks of gestation (6.3% at 37 weeks and 29.5% at 38 weeks) and 49.1% at 39 weeks of gestation. One neonatal death occurred. As compared with births at 39 weeks, births at 37 weeks and at 38 weeks were associated with an increased risk of the primary outcome (adjusted odds ratio for births at 37 weeks, 2.1; 95% confidence interval [CI], 1.7 to 2.5; adjusted odds ratio for births at 38 weeks, 1.5; 95% CI, 1.3 to 1.7; P for trend <0.001). The rates of adverse respiratory outcomes, mechanical ventilation, newborn sepsis, hypoglycemia, admission to the neonatal ICU, and hospitalization for 5 days or more were increased by a factor of 1.8 to 4.2 for births at 37 weeks and 1.3 to 2.1 for births at 38 weeks.
  
  
  CONCLUSIONS
  Elective repeat cesarean delivery before 39 weeks of gestation is common and is associated with respiratory and other adverse neonatal outcomes.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Alabama at Birmingham, 619 19th St. South, Birmingham, AL 35249, USA. alan.tita@obgyn.uab.edu
authors.forename: Alan T N
authors.initials: AT
authors.lastname: Tita
authors.forename: Mark B
authors.initials: MB
authors.lastname: Landon
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Yinglei
authors.initials: Y
authors.lastname: Lai
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Atef H
authors.initials: AH
authors.lastname: Moawad
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Meis
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Marshall
authors.initials: M
authors.lastname: Carpenter
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Baha M
authors.initials: BM
authors.lastname: Sibai
authors.forename: Oded
authors.initials: O
authors.lastname: Langer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
mesh_terms: D000293:Adolescent; D000328:Adult; D017604:Cesarean Section, Repeat / Q000009:adverse effects*; D015331:Cohort Studies; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D005865:Gestational Age; D006760:Hospitalization; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology / Q000209:etiology*; D007236:Infant, Small for Gestational Age; D007902:Length of Stay; D008423:Maternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome; D044469:Racial Groups; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology; D018805:Sepsis / Q000453:epidemiology; D014481:United States; D055815:Young Adult