Newborn evaluations of toxicity and withdrawal related to prenatal cocaineexposure

The literature on prenatal cocaine exposure is unclear whether immediate po stpartum effects on the infant are transient, related to either acute toxic ity of cocaine, or to a withdrawal effect as cocaine is metabolized, or whe ther they might persist. This prospective, longitudinal study was designed to test the hypotheses that newborns urine-positive for cocaine metabolites , compared to those exposed but urine-negative, and to nonexposed controls would (1) have poorer neurobehavioral scores (toxicity effect) and (2) wors en or demonstrate less improvement over the first week (withdrawal effect). We approached over 2500 pregnant women designated to deliver at our referr al hospital from public health clinics; 85% consented to participate in a l ongitudinal study. We excluded women < 18 years old with major chronic illn ess and prenatal drug use except cocaine, marijuana, alcohol and tobacco. F rom positive urine toxicologies or admissions in private, thorough intervie ws, 154 were identified as prenatal cocaine users; 154 were selected from n oncocaine users matched on socioeconomic status (SES), race, parity and loc ation of prenatal care (that related to perinatal risk), for a total sample size of 308. Included in this article are the 155 surviving infants who we re full-term, delivered vaginally and were well and available for testing o ver the first week postpartum. Infant urine specimens were collected, and n eurobehavorial testing was performed by certified, blinded examiners using the Neonatal Behavioral Assessment Scale on days 1, 2-4 and 5-7 postpartum. In toxicity analyses, controlling for amount of prenatal drug exposures, o nly autonomic regulation demonstrated significant overall and cocaine drug group effects. Urine-positive newborns had the poorest scores (i.e., more s tartles, tremors). However, given that planned comparisons were not signifi cant, these data provided little support for acute toxicity effects. In wit hdrawal analyses, only one significant change over time varied among exposu re groups. Those infants exposed and positive for cocaine metabolites incre ased their scores on regulation of state on days 2-4 and decreased them on days 5-7 (when withdrawal might be evident). However, their scores on days 5-7 were not significantly lower than their initial scores, nor different f rom the days 5-7 scores of the exposed negatives or control infants, lendin g little support for withdrawal effects. Our data support those of other co ntrolled studies in failing to demonstrate devastating early effects of pre natal cocaine exposure. They add to our understanding that effects observed do not appear to be related to acute toxicity nor to cocaine withdrawal. T he uncertainty of persistent effects of cocaine exposure warrants long-term follow-up. (C) 2001 Elsevier Science Inc. All fights reserved.