title: Urinary 3-phenoxybenzoic acid (3-PBA) levels among pregnant women in Mexico City: Distribution and relationships with child neurodevelopment.
abstract: BACKGROUND
  In recent years, pyrethroid pesticide use has increased in Mexico, the United States, and elsewhere, resulting in extensive human exposure. There is growing concern that pregnant women may be a particularly vulnerable population, as in utero fetal exposure during critical periods of development could adversely affect long-term neurobehavioral function.
  
  
  METHODS
  We measured maternal urinary 3-phenoxybenzoic acid (3-PBA) concentrations during the third trimester of pregnancy as a measure of in utero pyrethroid exposure to the fetus among participants in an established Mexico City birth cohort (n=187). In a subset of mothers, we measured 3-PBA during the first, second, and third trimester (n=21) to assess variability across pregnancy. We examined associations between third trimester 3-PBA concentrations and children's scores on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) from the Bayley Scales for Infant Development (BSID-IIS) at 24 and 36 months of age.
  
  
  RESULTS
  3-PBA was detected in 46% of all urine samples, with similar detection rates and geometric mean concentrations across pregnancy among the 21 participants who provided repeat samples. Participants in the medium and high 3-PBA categories (≥LOD) had lower MDI scores at 24 months compared to those in the low 3-PBA category (<LOD) after adjustment for covariates (ptrend=0.07), with slightly stronger associations among female children. The 3-level categorical variable for third trimester in utero 3-PBA was not associated with MDI scores at 36 months, or with PDI scores at either time point.
  
  
  CONCLUSIONS
  Considering the widespread agricultural and residential use of pyrethroids worldwide and the implications of cognitive and behavioral deficits, our findings indicate that additional study of in utero pyrethroid exposure and neurodevelopment in a larger study population is needed.
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Watkins
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Gamola Z
authors.initials: GZ
authors.lastname: Fortenberry
authors.affiliation: Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Brisa N
authors.initials: BN
authors.lastname: Sánchez
authors.affiliation: Department of Environmental Health, Emory University, Atlanta, GA, USA.
authors.forename: Dana Boyd
authors.initials: DB
authors.lastname: Barr
authors.affiliation: Department of Environmental Health, Emory University, Atlanta, GA, USA.
authors.forename: Parinya
authors.initials: P
authors.lastname: Panuwet
authors.affiliation: Division of Research on Public Health, National Institute of Perinatology, Mexico City, Mexico.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Schnaas
authors.affiliation: Division of Research on Public Health, National Institute of Perinatology, Mexico City, Mexico.
authors.forename: Erika
authors.initials: E
authors.lastname: Osorio-Valencia
authors.affiliation: National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: Maritsa
authors.initials: M
authors.lastname: Solano-González
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA.
authors.forename: Adrienne S
authors.initials: AS
authors.lastname: Ettinger
authors.affiliation: National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Ávila
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, ON, Canada.
authors.forename: Howard
authors.initials: H
authors.lastname: Hu
authors.affiliation: National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: Martha María
authors.initials: MM
authors.lastname: Téllez-Rojo
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA. Electronic address: meekerj@umich.edu.
authors.forename: John D
authors.initials: JD
authors.lastname: Meeker
mesh_terms: D001565:Benzoates / Q000009:adverse effects / Q000652:urine*; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D004785:Environmental Pollutants / Q000009:adverse effects / Q000652:urine*; D005260:Female; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D008431:Maternal-Fetal Exchange; D008800:Mexico; D009420:Nervous System / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000523:psychology / Q000652:urine
chemical_list: D001565:Benzoates; D004785:Environmental Pollutants; C017618:3-phenoxybenzoic acid
keywords: BSID-II; in utero; neurodevelopment; pesticide exposure; pyrethroid