title: Maternal health in sudden intrauterine unexplained death: do urinary tract infections protect the fetus?
abstract: OBJECTIVE
  To study the impact of maternal health and obstetric complications on the risk for sudden intrauterine unexplained death.
  
  
  METHODS
  All 76 cases of sudden intrauterine unexplained death and 165 explained stillbirths among singletons in Oslo, Norway (1986-1995) were compared with 582 controls. Information on maternal health was registered from antenatal health cards and the Medical Birth Registry of Norway. The effect of pregnancy duration was studied before logistic regression analysis corrected for pregnancy duration was performed.
  
  
  RESULTS
  Urinary tract colonization or infection in pregnancy was associated with a reduced risk for subsequent sudden intrauterine unexplained death (odds ratio [OR] 0.29 [0.12-0.74]), whereas insufficient physiologic hemodilution during pregnancy (lowest hemoglobin greater than 13 g/mL) increased the risk for sudden intrauterine unexplained death (OR 9.50 [1.30-69.3]). However, the risk for sudden intrauterine unexplained death remained unaffected by the total number of indicators of impaired maternal health during pregnancy, in contrast to significant impact on other stillbirths.
  
  
  CONCLUSIONS
  Urinary tract colonization or infection may offer protection against sudden intrauterine unexplained death. We hypothesize that the subsequent maternal immune response offers transplacental protection against lethal fetal infections by common pathogens of urinary tract infections. Other health indicators have little impact on sudden intrauterine unexplained death.
authors.affiliation: Department of Obstetrics & Gynecology, Rikshospitalet University Clinic, University of Oslo, Oslo, Norway. j.f.froen@klinmed.uio.no
authors.forename: J Frederik
authors.initials: JF
authors.lastname: Frøen
authors.forename: Randi A
authors.initials: RA
authors.lastname: Møyland
authors.forename: Ola Didrik
authors.initials: OD
authors.lastname: Saugstad
authors.forename: Babill
authors.initials: B
authors.lastname: Stray-Pedersen
mesh_terms: D005260:Female; D005313:Fetal Death / Q000453:epidemiology / Q000517:prevention & control*; D006438:Hemodilution; D006801:Humans; D008429:Maternal Welfare; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000503:physiopathology*; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000276:immunology / Q000503:physiopathology*