title: Maternal drinking water arsenic exposure and perinatal outcomes in inner Mongolia, China.
abstract: BACKGROUND
  Bayingnormen is a region located in western Inner Mongolia China, with a population that is exposed to a wide range of drinking water arsenic concentrations. The relationship between maternal drinking water arsenic exposure and perinatal endpoints (term birth weight, preterm birth, stillbirth and neonatal death) in this region was evaluated in this study.
  
  
  METHODS
  An analysis was conducted of all singleton deliveries in a defined geographical area of Inner Mongolia from December 1996 to December 1999 (n=9890). Outcome and covariate data were abstracted from prenatal care records. Exposure was based on well-water measures for the maternal subvillage. Mean birth weight at term was compared across four arsenic categories using analysis of covariance. ORs for stillbirth, preterm birth and neonatal death were estimated by logistic regression with arsenic exposure dichotomised at 50 microg/l.
  
  
  RESULTS
  Term birth weight was 0.05 kg higher (95% CI 0.02 to 0.08) in the highest exposure category (>100 microg/l) compared to the reference (below limit of detection to 20 microg/l). Arsenic >50 microg/l was associated with an increased risk of neonatal death (OR 2.01, 95% CI 1.12 to 3.59). No relationship was found between maternal arsenic exposure and preterm or stillbirth delivery.
  
  
  CONCLUSIONS
  At the levels observed in our study, arsenic does not appear to contribute to adverse birth outcomes. Exposure may play a role in neonatal death; however, the neonatal death rate in this population was low and this potential association merits further research.
authors.affiliation: Office of Research and Development, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, MD58A, Research Triangle Park, NC 27711, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Myers
authors.forename: D T
authors.initials: DT
authors.lastname: Lobdell
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Xia
authors.forename: H
authors.initials: H
authors.lastname: Ren
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: R K
authors.initials: RK
authors.lastname: Kwok
authors.forename: J L
authors.initials: JL
authors.lastname: Mumford
authors.forename: P
authors.initials: P
authors.lastname: Mendola
mesh_terms: D001151:Arsenic / Q000633:toxicity*; D001724:Birth Weight / Q000187:drug effects; D002681:China; D060766:Drinking Water / Q000737:chemistry*; D005260:Female; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000139:chemically induced; D050497:Stillbirth; D047929:Term Birth / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic