title: A longitudinal analysis of prenatal exposure to methylmercury and fatty acids in the Seychelles.
abstract: BACKGROUND
  Maternal fish consumption during pregnancy exposes the fetus simultaneously to methylmercury (MeHg) and long chain polyunsaturated fatty acids (LCPUFA). Data from the Seychelles Child Development Nutrition Study (SCDNS) showed a negative association of MeHg with child development when children were 30 months of age, only when controlling for LCPUFA. Concomitantly, n-3 LCPUFA were found to have a significant positive association only at 9 months. These findings suggest that the effects of MeHg and LCPUFA may vary with age over the first few years of life. We address this by including outcomes at two ages and adjusting for the child's age at testing.
  
  
  METHODS
  A longitudinal analysis utilizing linear mixed models was performed to assess the associations of maternal hair total mercury (THg, a biomarker for MeHg) and maternal LCPUFA with children's Bayley Scales of Infant Development Psychomotor Developmental Index (BSID-II PDI) at 9 and 30 months of age, and to determine whether these associations change over time. Data from 228 children were included.
  
  
  RESULTS
  Maternal hair MeHg had a negative effect on BSID PDI, while maternal n-3 LCPUFA had a positive effect. These effects did not change significantly from 9 to 30 months in this analysis.
  
  
  CONCLUSIONS
  The longitudinal analysis provides increased power for estimating the relationships of prenatal MeHg and LCPUFA exposures during child development. Significant associations of these exposures in opposite directions confirm the importance of LCPUFA in development and the need to adjust for maternal nutrition when studying prenatal MeHg exposure.
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
authors.forename: Abbie
authors.initials: A
authors.lastname: Stokes-Riner
authors.forename: Sally W
authors.initials: SW
authors.lastname: Thurston
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Myers
authors.forename: Emeir M
authors.initials: EM
authors.lastname: Duffy
authors.forename: Julie
authors.initials: J
authors.lastname: Wallace
authors.forename: Maxine
authors.initials: M
authors.lastname: Bonham
authors.forename: Paula
authors.initials: P
authors.lastname: Robson
authors.forename: Conrad F
authors.initials: CF
authors.lastname: Shamlaye
authors.forename: J J
authors.initials: JJ
authors.lastname: Strain
authors.forename: Gene
authors.initials: G
authors.lastname: Watson
authors.forename: Philip W
authors.initials: PW
authors.lastname: Davidson
mesh_terms: D000328:Adult; D000367:Age Factors; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D005260:Female; D006197:Hair / Q000737:chemistry; D006801:Humans; D007223:Infant; D018811:Maternal Exposure; D008767:Methylmercury Compounds / Q000032:analysis / Q000633:toxicity*; D009749:Nutrition Surveys; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D011597:Psychomotor Performance / Q000187:drug effects; D012750:Seychelles
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D008767:Methylmercury Compounds