title: Associations of birth outcomes with maternal polybrominated diphenyl ethers and thyroid hormones during pregnancy.
abstract: BACKGROUND
  Previous research has linked polybrominated diphenyl ether (PBDE) exposure to poor birth outcomes and altered thyroid hormone levels.
  
  
  OBJECTIVE
  We examined whether maternal PBDE serum levels were associated with infant birth weight (g), head circumference (cm), birth length (cm), and birth weight percentile for gestational age. We explored the potential for a mediating role of thyroid hormone levels.
  
  
  METHODS
  During 2008-2010, we recruited 140 pregnant women in their third trimester as part of a larger clinical obstetrics study known as Healthy Pregnancy, Healthy Baby. Blood samples were collected during a routine prenatal clinic visit. Serum was analyzed for PBDEs, phenolic metabolites, and thyroid hormones. Birth outcome information was abstracted from medical records.
  
  
  RESULTS
  In unadjusted models, a two-fold increase in maternal BDE 153 was associated with an average decrease in head circumference of 0.32cm (95% CI: -0.53, -0.12); however, this association was attenuated after control for maternal risk factors. BDE 47 and 99 were similarly negatively associated but with 95% confidence intervals crossing the null. Associations were unchanged in the presence of thyroid hormones.
  
  
  CONCLUSIONS
  Our data suggest a potential deleterious association between maternal PBDE levels and infant head circumference; however, confirmatory studies are needed in larger sample sizes. A mediating role of thyroid hormones was not apparent.
authors.affiliation: School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: mlmirand@umich.edu.
authors.forename: Marie Lynn
authors.initials: ML
authors.lastname: Miranda
authors.affiliation: School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Anthopolos
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Wolkin
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Stapleton
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000187:drug effects; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005865:Gestational Age; D055768:Halogenated Diphenyl Ethers / Q000097:blood*; D006801:Humans; D007223:Infant; D018811:Maternal Exposure / Q000009:adverse effects*; D011075:Polybrominated Biphenyls / Q000097:blood*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011263:Pregnancy Trimester, Third; D013963:Thyroid Hormones / Q000097:blood*; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; D013963:Thyroid Hormones; C517828:hexabrominated diphenyl ether 153; C511295:2,2',4,4'-tetrabromodiphenyl ether
keywords: Birth outcomes; Birth weight; Head circumference; Infant length; Polybrominated diphenyl ethers; Thyroid hormone