Cocaine Abuse in Pregnancy

To the Editor.—  The article entitled "Temporal Patterns of Cocaine Use in Pregnancy"1 should be useful in improving pregnancy outcomes, in that it demonstrates correlations between maternal cocaine abuse and low birth weight and between maternal cocaine abuse and poor neurological development.However, the lower rate of intrauterine growth retardation and prematurity in the group of infants whose mothers used cocaine only during their first trimesters, as opposed to the mothers who used cocaine throughout their pregnancies, should be interpreted with caution. One of the stated goals of the Perinatal Center for Chemical Dependence, where the study took place, was to facilitate the mothers' stopping their cocaine abuse. Therefore, an element of self-selection may be confounding the results. I suspect that mothers who were successful in abstaining from cocaine abuse after their first trimester may also have successfully stopped or reduced use of alcohol, tobacco, marijuana, caffeine, or other drugs