title: Low-level gestational exposure to mercury and maternal fish consumption: Associations with neurobehavior in early infancy.
abstract: BACKGROUND
  Studies examining the effects of low-level gestational methylmercury exposure from fish consumption on infant neurobehavioral outcomes in the offspring are limited and inconclusive. Our objective was to examine the effects of low-level gestational exposure to methylmercury on neurobehavioral outcomes in early infancy.
  
  
  METHODS
  We assessed neurobehavior of 344 infants at 5-weeks using the NICU Network Neurobehavioral Scale (NNNS). Gestational mercury exposure was measured as whole blood total mercury (WBTHg) in maternal and cord blood. We collected fish consumption information and estimated polyunsaturated fatty acid (PUFA) intake. We examined the association between gestational mercury exposure and NNNS scales using regression, adjusting for covariates.
  
  
  RESULTS
  Geometric mean of maternal and cord WBTHg were 0.64 and 0.72 μg/L, respectively. Most mothers (84%) reported eating fish during pregnancy. Infants with higher prenatal mercury exposure showed increased asymmetric reflexes among girls (p=0.04 for maternal WBTHg and p=0.03 for cord WBTHg), less need for special handling during the assessment (p=0.03 for cord WBTHg) and a trend of better attention (p=0.054 for both maternal WBTHg and cord WBTHg). Similarly, infants born to mothers with higher fish consumption or estimated PUFA intake also had increased asymmetric reflexes and less need for special handling. In models simultaneously adjusted for WBTHg and fish consumption (or PUFA intake), the previously observed WBTHg effects were attenuated; and higher fish consumption (or PUFA intake) was significantly associated with less need for special handling.
  
  
  CONCLUSIONS
  In a cohort with low level mercury exposure and reporting low fish consumption, we found minimal evidence of mercury associated detrimental effects on neurobehavioral outcomes during early infancy. Higher prenatal mercury exposure was associated with more frequent asymmetric reflexes in girls. In contrast, infants with higher prenatal mercury exposure and those whose mothers consumed more fish had better attention and needed less special handling, which likely reflect the beneficial nutritional effects of fish consumption.
authors.affiliation: Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati, OH, United States.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of Biostatistics and Epidemiology, Cincinnati, OH, United States.
authors.forename: Jane C
authors.initials: JC
authors.lastname: Khoury
authors.affiliation: Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of Biostatistics and Epidemiology, Cincinnati, OH, United States.
authors.forename: Heidi
authors.initials: H
authors.lastname: Sucharew
authors.affiliation: University of Cincinnati, College of Medicine, Department of Environmental Health, Cincinnati, OH, United States.
authors.forename: Kim
authors.initials: K
authors.lastname: Dietrich
authors.affiliation: Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati, OH, United States. Electronic address: kimberly.yolton@cchmc.org.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Yolton
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006801:Humans; D007223:Infant; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D011569:Psychiatric Status Rating Scales; D055815:Young Adult
chemical_list: D008767:Methylmercury Compounds
keywords: Fish consumption; Gestational exposure; Infancy; Methylmercury; NNNS; Neurobehavior