In utero p,p'-DDE exposure and infant neurodevelopment: a perinatal cohort in Mexico.
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.
Torres-Sánchez
Luisa
L
Instituto Nacional de Salud Pública, Morelos, México.
Rothenberg
Stephen J
SJ
Schnaas
Lourdes
L
Cebrián
Mariano E
ME
Osorio
Erika
E
Del Carmen Hernández
Maria
M
García-Hernández
Rosa M
RM
Del Rio-Garcia
Constanza
C
Wolff
Mary S
MS
López-Carrillo
Lizbeth
L
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
D004785:Environmental Pollutants; D007306:Insecticides; D007854:Lead; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT