title: Prenatal nitrate intake from drinking water and selected birth defects in offspring of participants in the national birth defects prevention study.
abstract: BACKGROUND
  Previous studies of prenatal exposure to drinking-water nitrate and birth defects in offspring have not accounted for water consumption patterns or potential interaction with nitrosatable drugs.
  
  
  OBJECTIVE
  We examined the relation between prenatal exposure to drinking-water nitrate and selected birth defects, accounting for maternal water consumption patterns and nitrosatable drug exposure.
  
  
  METHODS
  With data from the National Birth Defects Prevention Study, we linked addresses of 3,300 case mothers and 1,121 control mothers from the Iowa and Texas sites to public water supplies and respective nitrate measurements. We assigned nitrate levels for bottled water from collection of representative samples and standard laboratory testing. Daily nitrate consumption was estimated from self-reported water consumption at home and work.
  
  
  RESULTS
  With the lowest tertile of nitrate intake around conception as the referent group, mothers of babies with spina bifida were 2.0 times more likely (95% CI: 1.3, 3.2) to ingest ≥ 5 mg nitrate daily from drinking water (vs. < 0.91 mg) than control mothers. During 1 month preconception through the first trimester, mothers of limb deficiency, cleft palate, and cleft lip cases were, respectively, 1.8 (95% CI: 1.1, 3.1), 1.9 (95% CI: 1.2, 3.1), and 1.8 (95% CI: 1.1, 3.1) times more likely than control mothers to ingest ≥ 5.42 mg of nitrate daily (vs. < 1.0 mg). Higher water nitrate intake did not increase associations between prenatal nitrosatable drug use and birth defects.
  
  
  CONCLUSIONS
  Higher water nitrate intake was associated with several birth defects in offspring, but did not strengthen associations between nitrosatable drugs and birth defects.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Rural Public Health, Texas A&M Health Science Center, College Station, Texas 77843, USA. jdbrender@srph.tamhsc.edu
authors.forename: Jean D
authors.initials: JD
authors.lastname: Brender
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Weyer
authors.forename: Paul A
authors.initials: PA
authors.lastname: Romitti
authors.forename: Binayak P
authors.initials: BP
authors.lastname: Mohanty
authors.forename: Mayura U
authors.initials: MU
authors.lastname: Shinde
authors.forename: Ann M
authors.initials: AM
authors.lastname: Vuong
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Sharkey
authors.forename: Dipankar
authors.initials: D
authors.lastname: Dwivedi
authors.forename: Scott A
authors.initials: SA
authors.lastname: Horel
authors.forename: Jiji
authors.initials: J
authors.lastname: Kantamneni
authors.forename: John C
authors.initials: JC
authors.lastname: Huber
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
authors.forename: Martha M
authors.initials: MM
authors.lastname: Werler
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Kelley
authors.forename: John S
authors.initials: JS
authors.lastname: Griesenbeck
authors.forename: F Benjamin
authors.initials: FB
authors.lastname: Zhan
authors.forename: Peter H
authors.initials: PH
authors.lastname: Langlois
authors.forename: Lucina
authors.initials: L
authors.lastname: Suarez
authors.forename: Mark A
authors.initials: MA
authors.lastname: Canfield
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology* / Q000473:pathology; D002971:Cleft Lip / Q000139:chemically induced*; D002972:Cleft Palate / Q000139:chemically induced*; D015331:Cohort Studies; D004327:Drinking Behavior; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D006801:Humans; D017880:Limb Deformities, Congenital / Q000139:chemically induced*; D009566:Nitrates / Q000032:analysis / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D012044:Regression Analysis; D016136:Spina Bifida Occulta / Q000139:chemically induced*; D014481:United States / Q000453:epidemiology
chemical_list: D060766:Drinking Water; D009566:Nitrates