The purpose of this study was fourfold:

The study is a prospective, longitudinal investigation of 46 full-term infants who had positive urine toxicology screens for phencyclidine (PCP) and other drugs at birth and 39 non-drug-exposed control infants. Infants were followed from birth to 15 months of age. This study examined fetal growth impairment, as shown by subnormal head size and/or intrauterine growth retardation (IUGR) (i.e., birth weight below the tenth percentile), and later behavioral development in the groups of drug-exposed and non-drug-exposed infants. In order to access the range of possible causes of poorer developmental outcome, the investigators examined 89 variables such as maternal parity, maternal nicotine and alcohol use, caregiver education, and child placement outside of the biological home.