title: Pregnancy-induced hypertension and infant mortality in triplets.
abstract: OBJECTIVE
  To assess the effects of pregnancy-induced hypertension on infant mortality in triplets stratified by gestational age at birth.
  
  
  METHODS
  A retrospective cohort study was conducted using the linked 1995-2000 US birth/infant death database. Generalized estimating equations were used to evaluate the observed association.
  
  
  RESULTS
  Pregnancy-induced hypertension was associated with lesser neonatal mortality (odds ration [OR]: 0.34, 95% CI: 0.21, 0.54), postneonatal mortality (OR: 0.54, 95% CI: 0.30, 0.99) and infant mortality (OR, 0.37, 95% CI: 0.25, 0.55) in triplets. It was also associated with a decreased risk of neonatal death (OR, 0.38; 95% CI, 0.21-0.67), postneonatal death (OR, 0.45; 95% CI, 0.21-0.97), and infant death (OR, 0.39; 95% CI, 0.24-0.64) in early preterm triplets, whereas the association was not significant in late preterm or in full-term triplets.
  
  
  CONCLUSIONS
  Pregnancy-induced hypertension is associated with a decreased risk of infant mortality in triplets. This effect varies with gestational age at birth.
authors.affiliation: Clinical Epidemiology Program, Ottawa Health Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: X K
authors.initials: XK
authors.lastname: Chen
authors.forename: S W
authors.initials: SW
authors.lastname: Wen
authors.forename: G N
authors.initials: GN
authors.lastname: Smith
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: M C
authors.initials: MC
authors.lastname: Walker
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005865:Gestational Age; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000503:physiopathology*; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D047928:Premature Birth / Q000401:mortality* / Q000503:physiopathology; D012189:Retrospective Studies; D014310:Triplets; D014481:United States / Q000453:epidemiology