title: Prenatal exposure to manganese at environment relevant level and neonatal neurobehavioral development.
abstract: BACKGROUND
  Effects of prenatal Manganese (Mn) exposure at an environmental relevant level on neonatal neurodevelopment remains unclear.
  
  
  OBJECTIVE
  In the multi-center study, we assessed the impact of low level prenatal Mn exposure on neonatal behavioral neurological assessments (NBNA), and explore a threshold umbilical cord blood Mn on neonatal neurological development.
  
  
  METHODS
  We investigated 933 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Mn were measured and NBNA tests were conducted. The NBNA contains five clusters: behavior, active tone, passive tone, primary reflexes and general assessment with a maximal total score of 40. The score<37 is defined as low.
  
  
  RESULTS
  The median serum Mn concentration was 4.0 μg/L. Of the 933 infants, 44 (4.7%) had low NBNA. After adjusting for potential confounders, a high level of Mn (≥ 75th percentile ) was associated with a lower NBNA score (adjusted ß=-1.1, 95% CI: -1.4-0.7, p<0.01) and a higher risk of low NBNA (adjusted OR=9.4, 95% CI: 3.4-25.7, p<0.01). A nonlinear relationship was observed between cord serum Mn and NBNA after adjusting for potential confounders. NBNA score decreased with increasing Mn levels after 5.0 μg/L(LgMn ≥ 0.7). The cord serum Mn ≥ 5.0 μg/L had adverse effects on behavior, active tone and general reactions of clusters (p<0.001).
  
  
  CONCLUSIONS
  High prenatal Mn exposure even at an environmental relevant level, is associated with poor fetal neurobehavioral development in a nonlinear pattern. A threshold cord serum Mn of 5.0 μg/L existed for lower neonatal behavioral neurological assessments.
authors: MOE-Shanghai Key Laboratory of Children׳s Environmental Health, XinHua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai 200092, China.
authors: Xiao-Dan
authors: XD
authors: Yu
authors: MOE-Shanghai Key Laboratory of Children׳s Environmental Health, XinHua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai 200092, China.
authors: Jun
authors: J
authors: Zhang
authors: MOE-Shanghai Key Laboratory of Children׳s Environmental Health, XinHua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai 200092, China. Electronic address: yanch@shkeylab-ceh.org.
authors: Chong-Huai
authors: CH
authors: Yan
authors: MOE-Shanghai Key Laboratory of Children׳s Environmental Health, XinHua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai 200092, China.
authors: Xiao-Ming
authors: XM
authors: Shen
mesh_terms: D002657:Child Development / Q000187:drug effects*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000187:drug effects; D006801:Humans; D018730:Infant Behavior / Q000187:drug effects*; D007231:Infant, Newborn; D008297:Male; D008345:Manganese / Q000009:adverse effects* / Q000097:blood; D009420:Nervous System / Q000187:drug effects* / Q000254:growth & development*; D009460:Neurologic Examination; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D055815:Young Adult
chemical_list: D008345:Manganese
keywords: Epidemiology; Mn; Neonatal neurobehavioral development; Prenatal exposure