Association of DDT and DDE with birth weight and length of gestation in the Child Health and Development Studies, 1959-1967.

The pesticide p,p'-dichlorodiphenyltrichloroethane (DDT) and its persistent metabolite p,p'-dichlorodiphenyldichloroethylene (DDE) are associated with negative reproductive outcomes in animals. In humans, however, the findings are inconsistent. Using data from the Child Health and Development Studies, a longitudinal study of 20,754 pregnancies among San Francisco Bay Area women from 1959 to 1967, the authors examined the effects of maternal serum DDT and DDE concentrations on preterm birth, small-for-gestational-age birth, birth weight, and gestational age in 420 male subjects. Data were analyzed using multivariate logistic regression for preterm and small-for-gestational-age birth and linear regression for birth weight and gestational age. Median serum concentrations of DDE were 43 mug/liter (interquartile range: 32-57; range: 7-153) and of DDT were 11 mug/liter (interquartile range: 8-16; range: 3-72), several times higher than current US concentrations. 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 small-for-gestational-age birth, the adjusted odds ratio was 0.75 (95% CI: 0.44, 1.26) for DDE and 0.69 (95% CI: 0.73, 1.27) for DDT; none of the study results achieved statistical significance. Given the persistence of DDT in the environment and its continuing role in malaria control, studies using more robust data should continue to assess this relation.