DDE AND SHORTENED DURATION OF LACTATION IN A NORTHERN MEXICAN TOWN

Objectives. Worldwide declines in the duration of lactation are cause for public health concern. Higher levels of dichlorodiphenyl dichloroe thene (DDE) have been associated with shorter durations of lactation i n the United States. This study examined whether this relationship wou ld hold in an agricultural town in northern Mexico. Methods. Two hundr ed twenty-nine women were followed every 2 months from childbirth unti l weaning or until the child reached 18 months of age. DDE was measure d in breast milk samples taken at birth, and women were followed to se e how long they lactated. Results. Median duration was 7.5 months in t he lowest DDE group and 3 months in the highest. The effect was confin ed to those who had lactated previously, and it persisted after statis tical adjustment for other factors. These results are not due to overt ly sick children being weaned earlier. Previous lactation lowers DDE l evels, which produces an artifactual association, but simulations usin g best estimates show that an effect as large as that found here would arise through this mechanism only 6% of the time. Conclusions. DDE ma y affect women's ability to lactate. This exposure map be contributing to lactation failure throughout the world.