title: In utero p,p'-DDE exposure and infant neurodevelopment: a perinatal cohort in Mexico.
abstract: BACKGROUND
  Evidence suggests that p,p'-dichlorodiphenyldichloroethene (DDE) affects neurodevelopment in infants, although a critical exposure window has not yet been identified.
  
  
  OBJECTIVE
  Our goal was to assess the prenatal DDE exposure window and its effect on the psychomotor development index (PDI) and mental development index (MDI) during the first year of life.
  
  
  METHODS
  We recruited 244 children whose pregnancies and deliveries were uncomplicated, and whose mothers were monitored throughout the pregnancy. Participating mothers were not occupationally exposed to DDT (dichlorodiphenyltrichloroethane) but were residents of a zone in Mexico with endemic malaria. We measured serum levels of DDE before pregnancy and during each trimester of the pregnancy. We evaluated PDI and MDI of the Bayley Scales for Infant Development (BSID-II), at 1, 3, 6, and 12 months of age. We adjusted for quality of the home environment and maternal intellectual coefficient (IQ). We used generalized mixed-effects models for statistical analysis.
  
  
  RESULTS
  Third-trimester DDE level (7.8 +/- 2.8 ppb) was significantly higher than the level at baseline, first, and second trimesters, but the differences never exceeded 20%. Only DDE levels during the first trimester of pregnancy were associated with a significant reduction in PDI (every doubled increase of DDE level reduced the PDI 0.5 points). DDE was not associated with MDI.
  
  
  CONCLUSIONS
  A critical window of exposure to DDE in utero may be the first trimester of the pregnancy, and psychomotor development is a target of this compound. Residues of DDT metabolites may present a risk of developmental delay for years after termination of DDT use.
authors: Instituto Nacional de Salud Pública, Morelos, México.
authors: Luisa
authors: L
authors: Torres-Sánchez
authors: Stephen J
authors: SJ
authors: Rothenberg
authors: Lourdes
authors: L
authors: Schnaas
authors: Mariano E
authors: ME
authors: Cebrián
authors: Erika
authors: E
authors: Osorio
authors: Maria
authors: M
authors: Del Carmen Hernández
authors: Rosa M
authors: RM
authors: García-Hernández
authors: Constanza
authors: C
authors: Del Rio-Garcia
authors: Mary S
authors: MS
authors: Wolff
authors: Lizbeth
authors: L
authors: López-Carrillo
mesh_terms: D000328:Adult; D002657:Child Development / Q000187:drug effects*; D003634:DDT / Q000097:blood / Q000633:toxicity; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood / Q000633:toxicity*; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007306:Insecticides / Q000097:blood / Q000633:toxicity*; D007854:Lead / Q000097:blood; D018811:Maternal Exposure; D008431:Maternal-Fetal Exchange; D008800:Mexico / Q000453:epidemiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology; D011597:Psychomotor Performance / Q000187:drug effects
chemical_list: D004785:Environmental Pollutants; D007306:Insecticides; D007854:Lead; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT