RESUMO
Most studies of prenatal cocaine exposure have found gestational age or intrauterine growth deficits but few, if any, cognitive effects. In a large, well-controlled study we detected cognitive deficits in relation to heavy cocaine exposure. These findings demonstrate that prenatal exposure to cocaine at sufficiently high doses early in pregnancy has the potential to produce cognitive changes in infants and that more focused, narrow-band tests may be necessary to detect these subtle neurobehavioral effects. A total of 464 inner-city, black infants whose mothers were recruited prenatally on the basis of pregnancy alcohol and cocaine use were tested at 6.5, 12, and 13 months of age. Standard analyses, based on presence or absence of cocaine use during pregnancy, confirmed effects on gestational age but failed to detect cognitive effects. A new approach to identifying heavy users found that heavy exposure early in pregnancy was related to faster responsiveness on an infant visual expectancy test but to poorer recognition memory and information processing, deficits consistent with prior human and animal findings. These persistent neurobehavioral effects of heavy prenatal cocaine exposure appear to be direct effects of exposure and independent of effects on gestational age.
Assuntos
Cocaína , Transtornos Cognitivos/etiologia , Transtornos Relacionados ao Uso de Opioides/complicações , Complicações na Gravidez , Efeitos Tardios da Exposição Pré-Natal , Alcoolismo/complicações , Análise de Variância , Desenvolvimento Infantil , Feminino , Humanos , Lactente , Masculino , Gravidez , Fumar/efeitos adversosRESUMO
STUDY OBJECTIVES: To compare the effects of prenatal exposure to alcohol, smoking, and illicit drugs on birth size. DESIGN: Prospective, longitudinal correlational study, with statistical control for confounding. PARTICIPANTS: Four hundred seventeen black infants. Mothers recruited at first prenatal clinic visit on the basis of moderate-to-heavy use of alcohol or cocaine or both, plus a 5% random sample of lower-level drinkers and abstainers. MAIN RESULTS: Alcohol, smoking, opiates, and cocaine were each correlated with smaller birth weight, length, and head circumference (median r = -0.21; p < 0.001). However, when all four substances, gestational age, and six covariates were controlled statistically, birth weight related only to alcohol and smoking (p < 0.05), length only to alcohol (p < 0.05), and head circumference only to opiates (p < 0.01). Although smoking affected birth weight at all levels of exposure, a larger deficit was seen in relation to heavy drinking (509 gm) than to heavy smoking (269 gm). Alcohol and smoking did not affect birth size synergistically, and their effects were seen primarily in infants of women more than 30 years of age. CONCLUSIONS: The association of reduced birth weight and length with illicit drug use may be a consequence of simultaneous exposure of the fetus to alcohol and smoking. Opiate exposure is specifically related to reduced head circumference, and the effect of cocaine on birth size is primarily an indirect consequence of shorter gestation and poorer maternal nutrition.