Lisa M. Chiodo

New evidence for neurobehavioral effects of in utero cocaine exposure

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.

Validation of a new biomarker of fetal exposure to alcohol

OBJECTIVE To test the sensitivity and specificity of fatty acid ethyl esters (FAEEs) extracted from meconium to identify alcohol-using pregnant women with a sensitive and specific methodology, gas chromatography-tandem mass spectroscopy (GC/MS/MS). Study design Twenty-seven samples of meconium were obtained from infants from the mixed race community in Cape Town, South Africa, who were enrolled in a longitudinal neurobehavioral study. Maternal alcohol use was reported prospectively during pregnancy. FAEEs were isolated from meconium and quantitated by GC/MS/MS. RESULTS Ethyl oleate was the FAEE that correlated most strongly with maternal self-reported drinking, especially with the average ounces of absolute alcohol ingested per drinking day. Ethyl oleate was most strongly related to drinking in the second and third trimesters (Pearson r=.55 and.40, respectively). At a threshold of 1.5 average ounces of absolute alcohol ingested per drinking day, the area under the receiving operator characteristic curve was.92 (95% confidence interval, 0.74-0.97). Using a cut-off value of 32 ng/g, sensitivity was 84.2% and specificity was 83.3%. CONCLUSIONS Ethyl oleate concentration in meconium assayed by GC/MS/MS provides a highly sensitive and specific indicator of maternal alcohol use during pregnancy.

Maternal Age, Alcohol Abuse History, and Quality of Parenting as Moderators of the Effects of Prenatal Alcohol Exposure on 7.5-Year Intellectual Function

BACKGROUND In contrast to the extensive literature documenting IQ deficits in patients with fetal alcohol syndrome, effects on IQ have not generally been reported for children with alcohol-related neurodevelopmental disorder (ARND). This study examined the role of maternal age, MAST, and quality of parenting in moderating the effects of prenatal alcohol exposure on the WISC-III IQ test in moderate-to-heavily exposed children. METHODS A total of 337 inner-city African American children whose mothers were recruited prenatally were administered the WISC-III at 7.5 years. Alcohol exposure was assesed with a timeline follow-back interview administered at every prenatal clinic visit. Moderating effects of the three risk factors were examined by adding interaction terms to regression analyses and dichotomizing the moderators and performing separate regressions on the two groups. RESULTS Prenatal alcohol exposure was related to WISC-III Freedom from Distractibility but not to Full Scale IQ for the sample as a whole. However, among children born to older mothers, an alcohol effect emerged on Full Scale IQ and five of seven composite IQ scores. Similarly, adverse effects were seen among children of MAST-positive mothers and children whose parents provided less optimal cognitive stimulation. Each additional ounce of absolute alcohol consumed per day during pregnancy was associated with a 2.9-point decrease in Full Scale IQ and a 5.6-point decrement on Freedom from Distractibility. CONCLUSIONS This study is the first to demonstrate IQ effects among children with ARND born to older and MAST-positive mothers, particularly in relation to first-trimester drinking. These findings suggest that there are subgroups of more vulnerable and severely affected children whose intellectual performance is compromised. A moderate- to heavy-drinking mother who has given birth to an unaffected child when she was younger needs to be warned that her risk of having an adversely affected child increases as she grows older.

Breastfeeding Effects on Intelligence Quotient in 4- and 11-Year-Old Children

Objective A study of preterm children found an IQ advantage among those who were breastfed as infants after controlling for maternal social class and educational status. However, this advantage needs to be examined in light of other maternal characteristics, such as maternal IQ and parenting skills, which were not measured in that study and which have been found to be related to breastfeeding. Methodology. IQ was assessed in 323 children at 4 years of age on the McCarthy Scales of Childrens Abilities and the Peabody Picture Vocabulary Test-Revised and in 280 children on the Wechsler Intelligence Test for Children-Revised at 11 years of age. Results. Children who were breastfed in infancy had significantly higher scores on IQ tests at both ages, even after adjusting for social class and education, confirming the earlier findings and extending them to a predominantly full-term sample. However, the effect of breastfeeding was no longer significant after adjusting for maternal IQ assessed on the Peabody Picture Vocabulary Test-Revised and for parenting skills assessed on the Home Observation for Measurement of the Environment. Significant relations between breastfeeding and Woodcock Reading Achievement scores at 11 years were also reduced to nonsignificant levels after the inclusion of maternal IQ and the Home Observation for Measurement of the Environment. Conclusions. These findings suggest that the observed advantage of breastfeeding on IQ is related to genetic and socioenvironmental factors rather than to the nutritional benefits of breastfeeding on neurodevelopment. They should not be interpreted as detracting from the medical benefits associated with breastfeeding.

Effects of prenatal alcohol and cocaine exposure on infant cortisol levels

Elevated corticosterone levels to stress have been found in adult rats exposed prenatally to alcohol, but little is known about the effects of prenatal alcohol exposure on the cortisol response in humans. To date, one study has found that crack/cocaine was related to depressed newborn cortisol levels following a heel prick. In the present study saliva samples were obtained before and after a blood draw from 83 inner-city African American 13-month-old infants exposed prenatally to alcohol, cocaine, and other illicit drugs. Post-blood draw cortisol levels did not differ from basal levels in many of the infants, confirming recent studies indicating adaptation of the adrenocortical response to this type of stress at this age. Maternal depression and emergence of teeth were positively related to cortisol levels. Alcohol exposure was related to elevated basal levels, cocaine to lower basal levels. As predicted from animal findings, heavy alcohol exposure was related to elevated poststress cortisol levels.

Representations of Self Across the Life Span

This research extends a cognitive-developmental approach to examining age differences in self-representation from adolescence to mature adulthood and later life. The authors suggest that mature adults move from representations of self that are relatively poorly differentiated from others or social conventions to ones that involve emphasis on process, context, and individuality. Participants (n men = 73, n women = 76), ranging in age from 11 to 85 years, provided spontaneous accounts of their self-representations and responded to measures assessing cognitive and emotional functioning and broad dimensions of personality. On average, self-representation scores peaked in middle-aged adults and were lowest in the preadolescent and older adult age groups. Level of self-representation was related to cognitive and personality variables, but there was some evidence that the pattern of correlates shifted from younger (ages 15-45) to older (ages 46-85) age segments.

Prenatal cocaine: Quantity of exposure and gender moderation

ABSTRACT. Animal but few human studies have demonstrated gender-influenced differences in outcome related to prenatal cocaine exposure. Pregnant participants in a prospective pregnancy study were interviewed for drug use. Exposure was considered positive if history or laboratory tests were positive. An ordinal measure of exposure was also constructed. Six years later, the child and primary caretaker were tested to assess drug use in the home since birth and teacher-assessed child behavior. Data were complete for 473 children (204 cocaine exposed). Twenty-four of the exposed children (12%) were considered to have persistent pregnancy exposure based on positive urine screen at delivery. Boys with any prenatal cocaine exposure scored significantly higher (more problem behaviors) than nonexposed boys on the hyperactivity item. In contrast, no similar cocaine effect was observed for girls. When cocaine exposure was expressed as the three-level ordinal variable, boys, but not girls, with persistent exposure had more behavior problems (0.5 to 1.0 SD higher). Even after control for important covariates, boys with persistent exposure had more problems in central processing, motor skills, handling abstract concepts, and passivity to the environment. The magnitude of the relations reported in this research were moderate to large. In summary, both gender and the level of exposure had a significant behavioral effect on school-age behavior. In these analyses, the behavior of boys, but not girls, prenatally exposed to cocaine was significantly and negatively affected, and these findings remained after control for covariates, including prenatal alcohol or other illicit drug exposures and postnatal drug use in the home.

Just Say “I Don't”: Lack of Concordance Between Teen Report and Biological Measures of Drug Use

BACKGROUND: Prevalence estimates of illicit drug use by teens are typically generated from confidential or anonymous self-report. While data comparing teen self-report with biological measures are limited, adult studies identify varying degrees of under-reporting. METHODS: Hair analyses for cocaine, opiates and marijuana were compared to confidential teen self- and parent-reported teen drug use in a longitudinal cohort of >400 high-risk urban teens and parents. RESULTS: Both teens and parents substantially underreported recent teen cocaine and opiate use. However, compared with parents, teens were more likely to deny biomarker-verified cocaine use. Teen specimens (hair) were 52 times more likely to identify cocaine use compared with self-report. Parent hair analyses for cocaine and opiate use were 6.5 times and 5.5 times, respectively, more likely to indicate drug use than were parental self-report. The lack of concordance between self-report and bioassay occurred despite participants knowledge that a “certificate of confidentiality” protected both teen and adult participants, and that the biological specimens would be tested for drugs. CONCLUSIONS: These findings confirm prior reports of adult under-reporting of their own drug use while extending our understanding of teens self-admitted drug use. The lack of concordance between teen self- or parent-reported teen drug use and biomarkers confirm our concerns that both teen- and parent-reported teen drug use is limited, at least for youth in high-risk urban settings. Methods of ascertainment other than self- or parent-report must be considered when health care providers, researchers and public health agencies attempt to estimate teen drug-use prevalence.

A 14-year retrospective maternal report of alcohol consumption in pregnancy predicts pregnancy and teen outcomes

Detecting patterns of maternal drinking that place fetuses at risk for fetal alcohol spectrum disorders (FASDs) is critical to diagnosis, treatment, and prevention but is challenging because information on antenatal drinking collected during pregnancy is often insufficient or lacking. Although retrospective assessments have been considered less favored by many researchers due to presumed poor reliability, this perception may be inaccurate because of reduced maternal denial and/or distortion. The present study hypothesized that fetal alcohol exposure, as assessed retrospectively during child adolescence, would be related significantly to prior measures of maternal drinking and would predict alcohol-related behavioral problems in teens better than antenatal measures of maternal alcohol consumption. Drinking was assessed during pregnancy, and retrospectively about the same pregnancy, at a 14-year follow-up in 288 African-American women using well-validated semistructured interviews. Regression analysis examined the predictive validity of both drinking assessments on pregnancy outcomes and on teacher-reported teen behavior outcomes. Retrospective maternal self-reported drinking assessed 14 years postpartum was significantly higher than antenatal reports of consumption. Retrospective report identified 10.8 times more women as risk drinkers (≥ one drink per day) than the antenatal report. Antenatal and retrospective reports were moderately correlated and both were correlated with the Michigan Alcoholism Screening Test. Self-reported alcohol consumption during pregnancy based on retrospective report identified significantly more teens exposed prenatally to at-risk alcohol levels than antenatal, in-pregnancy reports. Retrospective report predicted more teen behavior problems (e.g., attention problems and externalizing behaviors) than the antenatal report. Antenatal report predicted younger gestational age at birth and retrospective report predicted smaller birth size; neither predicted teen IQ. These results suggest that if only antenatal, in-pregnancy maternal report is used, then a substantial proportion of children exposed prenatally to risk levels of alcohol might be misclassified. The validity of retrospective assessment of prior drinking during pregnancy as a more effective indicator of prenatal exposure was established by predicting more behavioral problems in teens than antenatal report. Retrospective report can provide valid information about drinking during a prior pregnancy and may facilitate diagnosis and subsequent interventions by educators, social service personnel, and health-care providers, thereby reducing the life-long impact of FASDs.

Prenatal and postnatal cocaine exposure predict teen cocaine use

Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n=316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use.