Mothers with CE had less prenatal care, were older (~ 4 years), slightly less educated, and primarily unmarried with lower vocabulary scores (). Infants with CE were exposed to more alcohol, marijuana, and tobacco prenatally, had lower birthweight, length, and head circumference, and were more likely preterm ().
Maternal and Current Caregiver Characteristics by Prenatal Cocaine Exposure
By 9 years, there were 11 child deaths, 8 children with CE and 3 children with NCE (χ2 = 1.9, p < .17), and 371 (192 CE, 179 NCE) children (92%) were assessed. 44 children with CE and 8 children with NCE (χ2 = 26.2, p < .001) were in adoptive/foster care. Caregiver and home environment characteristics did not differ except that caregivers of children with CE had lower vocabulary scores, and used more tobacco in the previous month. Of 33 children not seen, 18 children with CE were more likely to be white, of higher birthweight and head circumference, with lower Hobel risk scores and had mothers with lower WAIS-R picture completion scores than participants. The 15 children with NCE not seen had lower alcohol exposure, birth length, and Hobel risk scores and higher gestational age than the participants with NCE.
Groups did not differ in school grade placement, repeated grades, or special education. Children with CE were marginally more likely to receive a mental health service [58, (30.9%) vs. 40 (23%) χ2
= 3.1, p < .08]. 293 children (150 CE, 143 NCE) had blood levels determined.(4
) Elevated lead exposure (≥ 10 mg/dl) was marginally lower for children with CE, 26 (17.3%) vs. 38 (26.6%) NCE (χ2
= 3.6, p < .056), and more children with CE (9 (4.69%) than NCE (2 (1.12%), χ2
= 4.1, p = 0.04) had IDA.
The MANOVA on the Domain IQ scores of the WISC-IV was significant (Wilks’ λ = 0.97 [F = 2.46, df = 4,365, p < .045]) as was the MANCOVA on Perceptual Reasoning IQ (Wilks’ λ = 0.98 [F = 2.65, df = 3,366, p < .049]). Children with CE had lower Perceptual Reasoning IQ’s (M’s = 87.6 ± 1 vs. 90.6 ± 1, F = 3.9, df, 6,355, p < .05), and a higher percentage of children with significant deficits, (i.e. < 85 standard score), 81 (42% CE) vs. 58 (32% NCE), χ2 = 3.9, p < .047. Moreover, when classified into heavier and lighter exposure groups, there were greater effects with heavier exposure (). There were no cocaine effects on the WJTOA.
Figure 1 Perceptual reasoning IQ by level of cocaine exposure (F=3.97, df=9, 264, p=.02) with significant post-hoc mean difference between No cocaine group and Heavier cocaine exposed group (p=.0207). The heavier cocaine group was determined by benzoylecgonine (more ...)
The relative contributions of cocaine, other drugs, lead, IDA, and HOME environment are shown in (available at www.jpeds.com
). Significant cocaine effects became more pronounced once lead and IDA were controlled. CE was marginally related to a lower likelihood of achieving an IQ score above the normative mean. The concentration of benzoylecgonine was negatively related to Perceptual Reasoning IQ (β = −.15, SE = .26, p < .03), and matrix reasoning (β = −.17, SE = .05, p < .02), and m-OH- benzoylecgonine was marginally related to matrix reasoning (β = −.11, SE = .06, p < .10). Cocaine effects on Perceptual Reasoning IQ were mediated by lower head circumference at birth.
Adjusted Effects of Drug, Alcohol, IDA, and Lead Exposures on Child Outcomes (n = 293)*
Alcohol exposure predicted poorer Working Memory IQ, vocabulary and marginally lower Full Scale IQ. Adverse lead effects were detectable on Verbal Comprehension, Perceptual Reasoning and Full Scale IQ; academic achievement; and a lower likelihood of an IQ above the mean. IDA was associated with lower scores on similarities, math and marginally to poorer reading skills. Marijuana exposure was related to poorer performance on coding, which measures processing speed.
The quality of the home environment and birth mother vocabulary predicted multiple outcomes, including Verbal Comprehension IQ, similarities, vocabulary, Perceptual Reasoning IQ and its subscales, Working Memory, Processing Speed, and Full Scale IQ’s, (all p’s < .05). Lower maternal parity at the study child’s birth predicted higher Verbal Comprehension IQ (p <.05), as did the current caregiver’s alcohol use (p < .05). Caregiver WAIS-R block design score predicted child score (p < .05) and birth mother psychological distress at childbirth marginally (p < .10) predicted Matrix reasoning. There were no moderating effects of sex or race.
Children with CE in foster/adoptive care had caregivers with better vocabulary and less psychological distress than those in maternal/relative care (). Lead exposure was also lower, but they had almost twice the level of prenatal cocaine exposure. Children with CE in foster/adoptive care were less likely to achieve an IQ > 100 (the normative mean) than the group with NCE (adjusted O.R. = .11 [95%C.I., 0.01–0.89], p < .039). Only one child with CE in foster/adoptive care attained an IQ score > 100. There was no difference in mean IQ or in the incidence of mental retardation.
Comparisons of Key Environmental Characteristics and Child Outcomes by Caregiver Group