title: The relationship between water intake and foetal growth and preterm delivery in a prospective cohort study.
abstract: BACKGROUND
  Interpretation of previous associations between water intake and adverse birth outcomes is challenging given that amount and type of water consumed can be non-specific markers of exposure or underlying behavioural characteristics. We examined the relationship between water intake measures and adverse birth outcomes in participants from three study sites in the United States.
  
  
  METHODS
  Using a prospective cohort study, we examined daily intake of bottled, cold tap, total tap, and total water in relation to birth weight and risk of small-for-gestational-age (SGA) among term births and risk of preterm delivery.
  
  
  RESULTS
  Based on water consumption data collected between 20-24 weeks of gestation, the adjusted mean birth weight was 27 (95% confidence interval [CI]: -34, 87), 39 (95% CI: -22, 99), and 50 (95% CI: -11, 110) grams higher for the upper three total water intake quartiles (> 51-78, > 78-114, and > 114 ounces/day) compared to the lowest quartile (≤ 51 ounces/day). Adjusted birth weight results were similar for bottled water, cold tap water, and total tap water intake. An exposure-response gradient was not detected for either preterm delivery or SGA with increasing total water intake and total tap water intake, but adjusted relative risks for all three upper quartiles were below 1.0 (range: 0.6-0.9) for SGA.
  
  
  CONCLUSIONS
  These data suggest that high water intake may be associated with higher mean birth weight following adjustment for confounding.
authors.affiliation: National Center for Environmental Assessment, US Environmental Protection Agency, Cincinnati, Ohio, USA. wright.michael@epa.gov
authors.forename: J Michael
authors.initials: JM
authors.lastname: Wright
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Hoffman
authors.forename: David A
authors.initials: DA
authors.lastname: Savitz
mesh_terms: D000328:Adult; D004326:Drinking; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D015999:Multivariate Analysis; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D011446:Prospective Studies; D012306:Risk; D014481:United States / Q000453:epidemiology