title: Waiting for postterm in healthy women, is it an accident waiting to happen?
abstract: OBJECTIVE
  To establish whether postterm pregnancies are associated with adverse perinatal outcomes in a linear fashion.
  
  
  METHODS
  A retrospective cohort study investigating perinatal outcomes in singleton term (≥ 37 weeks gestation) and postterm pregnancies was conducted. Deliveries occurred between the years 1988 and 2010. Parturients were classified into three groups according to their gestational age: 37-39 + 6, 40-41 + 6 and over 42 weeks' gestation (postterm). Statistical analysis included multiple logistic regression model to control for possible confounders.
  
  
  RESULTS
  Out of 202,462 deliveries, meeting the inclusion criteria, during the study period, 47.7% occurred at 37-39 + 6 weeks, 47.4% occurred at 40-41 + 6 weeks and 4.9% were postterm. Fertility treatments, diabetes mellitus, hypertensive disorders, intrauterine growth restriction (IUGR) and premature rupture of membranes (PROM) were less likely to be associated with postterm pregnancies. However, postterm was found as a significant risk factor for labor complications and adverse perinatal outcome including perinatal mortality. Using a multivariable logistic regression model, controlling for confounders such as maternal age and macrosomia, postterm was found to be an independent risk factor for perinatal mortality (adjusted OR = 1.5; 95% CI = 1.20-2.0; p < 0.001).
  
  
  CONCLUSIONS
  Although postterm pregnancies were less likely to be associated with obstetrical risk factors and complications such as fertility treatments, diabetes mellitus, hypertensive disorders, IUGR and PROM, postterm is an independent risk factor for perinatal mortality.
authors.affiliation: Department of Obstetrics and Gynecology, Soroka University Medical Center, Ben-Gurion University of Negev, Beer-Sheva, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Bel-Ange
authors.forename: Avi
authors.initials: A
authors.lastname: Harlev
authors.forename: Adi Y
authors.initials: AY
authors.lastname: Weintraub
authors.forename: Eyal
authors.initials: E
authors.lastname: Sheiner
mesh_terms: D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007233:Infant, Postmature; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult