title: Disaster-related prenatal maternal stress influences birth outcomes: project Ice Storm.
abstract: BACKGROUND
  Previous research suggests that prenatal maternal stress (PNMS) impacts birth outcomes, but many human studies cannot distinguish between the effects of different types of stressors or examine effects of exposure timing on outcomes.
  
  
  OBJECTIVE
  Our goal was to determine how timing and severity of exposure during pregnancy to objective and subjective stress due to a natural disaster influenced gestation length and fetal growth patterns.
  
  
  METHODS
  We assessed objective and subjective PNMS levels among 172 women exposed to an ice storm during or shortly before pregnancy. We analyzed associations between PNMS levels and outcomes (gestation length, birth weight, birth length, head circumference, and growth ratios), controlling for other variables such as age, obstetric complications, socioeconomic status, and trait anxiety.
  
  
  RESULTS
  Gestation lengths and predicted birth weights were shorter among participants exposed to the ice storm during early to mid pregnancy, compared to 3rd trimester and pre-pregnancy exposure. Birth lengths were shorter in the sample compared to population references, and predicted values were shorter among participants with a "discrepancy" between their objective and subjective PNMS levels. High objective PNMS levels predicted smaller head circumferences in early pregnancy, but we also observed patterns in predicted values of head circumference to birth length ratios suggesting the sparing of brain development relative to birth length among boys in early pregnancy. These sparing effects decreased in later pregnancy.
  
  
  CONCLUSIONS
  Exposure to stressful events during pregnancy influences birth outcomes independently of other factors. Exposure timing, newborn sex, and the type of stressor influence the effects observed.
authors.affiliation: Douglas Hospital Research Center, 6875 LaSalle Blvd., Verdun QC, Canada H4H 1R3.
authors.forename: Kelsey N
authors.initials: KN
authors.lastname: Dancause
authors.forename: David P
authors.initials: DP
authors.lastname: Laplante
authors.forename: Carolina
authors.initials: C
authors.lastname: Oremus
authors.forename: Sarah
authors.initials: S
authors.lastname: Fraser
authors.forename: Alain
authors.initials: A
authors.lastname: Brunet
authors.forename: Suzanne
authors.initials: S
authors.lastname: King
mesh_terms: D049628:Body Size; D004190:Disasters; D005260:Female; D047109:Fetal Development; D005865:Gestational Age; D006801:Humans; D007053:Ice; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D011792:Quebec; D012044:Regression Analysis; D012737:Sex Factors; D013315:Stress, Psychological; D013997:Time Factors
chemical_list: D007053:Ice