RESUMO
Anogenital distance (AGD) at birth is regarded as a useful measurement that reflects the prenatal androgenic status in rodents. However, the impact of xenoantiandrogens on human development is largely unknown. The aim of this study was to evaluate the potential antiandrogenic impact of prenatal DDT metabolites (p,p'-DDE and p,p'-DDT) exposure on infant AGD, using a non-age-dependent anal position index (API). As part of an ongoing perinatal cohort study on the effects of organochlorine pesticides in children's neurodevelopment, we conducted a cross-sectional study in 71 infants (37 males and 34 females). Maternal serum levels of DDT metabolites (p,p'-DDE and p,p'-DDT) before and during each trimester of pregnancy were determined by electron capture gas-liquid chromatography. During postnatal home visits at 3, 6, and 12 or 18 months of age, the children's weight and API were evaluated. Multiple lineal regression models were used to estimate the potential endocrine disruptor activity of prenatal p,p'-DDE exposure. Boys had significantly higher API values than girls (0.6 versus 0.5; P < 0.001). Only among boys, a doubling increase of maternal p,p'-DDE serum levels during the first trimester of pregnancy, were associated with a significant reduction of API (beta=-0.02; P= 0.02). No effect of p,p'-DDT on AGD was observed. Evidence of the effect of prenatal p,p'-DDE on external genital differentiation is scarce and not consistent in the literature. Further studies are needed to confirm a hormonal disruptive effect on the development of external genitalia, due not only to p,p'-DDE but also due to other antiandrogenic persistent compounds.
Assuntos
Canal Anal/anormalidades , Diclorodifenil Dicloroetileno/toxicidade , Exposição Materna , Canal Anal/efeitos dos fármacos , Antagonistas de Androgênios/metabolismo , Estudos de Coortes , Sistema Endócrino/efeitos dos fármacos , Feminino , Humanos , Recém-Nascido , Masculino , México , Gravidez , Primeiro Trimestre da Gravidez , Análise de Regressão , Fatores SexuaisRESUMO
BACKGROUND: Evidence suggests that p,p'-dichlorodiphenyldichloroethene (DDE) affects neurodevelopment in infants, although a critical exposure window has not yet been identified. OBJECTIVES: 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.