Cognitive functioning in 8- to 18-month old drug-exposed infants.

Abstract

This study examined the cognitive functioning in 236 infants at 8 and 18 months of age. Thirty-seven infants were heavily exposed to cocaine in-utero, 30 were lightly exposed, and 169 were not exposed to cocaine. Cognitive functioning was evaluated with the Bayley Scales of Infant Development (2nd ed.; N. Bayley, 1993) at both ages. Infant information processing was also assessed with an infantcontrolled habituation procedure. Results indicated that (a) infants of cocaine-abusing women had higher neonatal medical and environmental risk scores; (b) at 8 months, exposure groups did not differ in Psychomotor Development Index, Mental Development Index (MDI) scores, or recovery to a novel stimulus; and (c) infants heavily exposed to cocaine or high environmental risk had a decrease in MDI scores from 8 to 18 months. These results were obtained when neonatal medical and environmental risk, as well as polydrug exposure, were controlled.In examining whether prenatal exposure to cocaine impairs later cognitive functioning, research on humans continues to provide equivocal results. The ambiguous nature of outcome findings is due to methodological problems typically associated with behavioral toxicology research. In studies in which researchers are attempting to find relations between prenatal cocaine and some aspect of postnatal development, researchers must contend with a host of methodological problems, including (a) the potential confounding effects of other substances of abuse and poor maternal health and nutrition, (b) sensitive and valid measurement of infant outcome behaviors, and (c) differential effects of the postnatal child-rearing environment (e.g.,

The effects of prenatal cocaine use on infant development

“…This association between PCE and motor development has been reported previously by some researchers [34,82], but not by others [2,4,43,58]. This is an area that is in need of further investigation.…”

“…Most investigators have also not found detrimental effects of PCE on infant motor development, as measured by the Psychomotor Development Index (PDI) of the BSID or by the Peabody Developmental Motor Scales [2][3][4]12,13,21,34,36,41,43,[58][59][60]65,83]. By contrast, Singer et al [82] found that PCE was associated with lower PDI scores at about 17 months.…”

“…Only a few studies have reported detrimental effects on MDI scores. Alessandri, Bendersky, and Lewis [2] found an effect of PCE on the MDI at 18 months of age, but not at 8 months. Singer et al [82], in a sample recruited from a high-risk follow-up clinic, reported that prenatal exposure to cocaine was associated with lower MDI scores at approximately 17 months of age.…”

Augmented D1 Dopamine Receptor Signaling and Immediate-Early Gene Induction in Adult Striatum After Prenatal Cocaine

“…Numerous studies reporting findings from exposed offspring have linked prenatal cocaine exposure with microcephaly (5), low birth weight and preterm births (6), altered or delayed motor development (7), global hypertonia and coarse tremor (8), reduced cognitive development (9), and a subtle reduction in IQ (3) in a subset of exposed offspring. However, the data remains elusive as to the independent contribution of prenatal cocaine vs. confounding variables such as poly-drug use, poor prenatal; care, adverse living situations, and compromised maternal health in contributing to adverse postnatal neuro-behavioral outcomes.…”

Conceptual model for maternal behavior among polydrug cocaine-using mothers: The role of postnatal cocaine use and maternal depression.

“…Indeed, a number of studies have noted that the caregiving environment of children exposed to cocaine and other substances in the prenatal period is often unstable and negative (Alessandri, Bendersky, & Lewis, 1998;Brown, Bakeman, Coles, Platzman, & Lynch, 2004;Singer et al, 2002). This is especially important given recent reports that cocaineexposed children in nonmaternal, nonkin care in the first 2 years of life have more positive outcomes at 2 years of age compared with those raised by their biological parent (Brown et al, 2004).…”