Association of DDT and DDE With Birth Weight and Length of Gestation in the Child Health and Development Studies, 1959???1967

Abstract

In animal studies, exposure to organochlorine pesticides such as DDT and its metabolite DDE is associated with adverse reproductive outcomes. Human studies have, however, yielded inconsistent results. The authors analyzed data from the Child Health and Development Studies, a longitudinal follow-up study of 20,754 pregnancies in women living in the San Francisco Bay area in the years 1959-1967. Relationships were sought between maternal serum levels of DDT and DDE and preterm birth, small-for-gestational-age (SGA) birth, birth weight, an gestational age in 420 males. Multivariate logistic regression analysis was used for data on preterm and SGA births, and linear regression analysis for birth weight and gestational age. The median maternal serum levels of DDE and DDT were 43 and 11 μg/L, respectively, figures several times higher than current concentrations in the United States. The adjusted odds ratio for preterm birth was 1.28 (95% confidence interval [CI], 0.73-2.23) for DDE and 0.94 (95% CI, 0.50-1.78) for DDT. For SGA birth, the odds ratios were 0.75 (95% CI, 0.44-1.26) for DDE and 0.69 (95% CI, 0.73-1.27) for DDT. No significant relationships or even trends were found between maternal serum concentrations of DDT or DDE and birth weight or length of gestation. None of the reproductive outcomes were significantly associated with the DDE:DTT ratio. These findings do not rule out the possibility that serum pesticide levels may have modest effects on reproductive outcomes, but there is no epidemiologic support for strong causal relationships between DDT or DDE and unfavorable outcomes in male infants. Further studies are appropriate because of the major current role of DDT in preventing malaria.