title: Outcomes of pregnancy beyond 37 weeks of gestation.
abstract: OBJECTIVE
  The aim of the study was to evaluate pregnancy outcomes by weeks of gestation. A second aim was to assess the outcomes in groups with spontaneous or induced labor.
  
  
  METHODS
  This was a prospective cohort study of singleton pregnancies delivered after 37 weeks of pregnancy covering a well defined region in Norway from 1990 to 2001 (N = 27,514). Linear regression, chi 2 tests, and multivariable logistic regression analysis were used.
  
  
  RESULTS
  Maternal complications varied with gestational age, and were lowest at 39 weeks and highest postterm (cesarean delivery 12.3-21.6%, operative vaginal delivery 10.7-15.4%, maternal hemorrhage 9.7-14.6%). Poor neonatal outcome varied with gestational age only for spontaneous labors (Apgar at 5 minutes less than 7 1.0-2.3%, pH less than 7.10 3.4-5.2%), whereas induction of labor was a risk factor for delivery complications (odds ratio 1.3-2.8), independent of gestational weeks.
  
  
  CONCLUSIONS
  Poor pregnancy outcomes vary with gestational age. Postterm pregnancy and induced labor are prognostic factors for poor outcome.
authors.affiliation: Department of Obstetrics and Gynecology and National Center for Fetal Medicine, St. Olavs Hospital, University Hospital, Trondheim, Norway. runa.heimstad@ntnu.no
authors.forename: Runa
authors.initials: R
authors.lastname: Heimstad
authors.forename: Pål R
authors.initials: PR
authors.lastname: Romundstad
authors.forename: Sturla H
authors.initials: SH
authors.lastname: Eik-Nes
authors.forename: Kjell A
authors.initials: KA
authors.lastname: Salvesen
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D016009:Chi-Square Distribution; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000379:methods / Q000706:statistics & numerical data*; D007743:Labor, Obstetric / Q000502:physiology; D016014:Linear Models; D016015:Logistic Models; D009664:Norway; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011273:Pregnancy, Prolonged; D011446:Prospective Studies; D012307:Risk Factors; D014620:Vacuum Extraction, Obstetrical / Q000706:statistics & numerical data