Dose-response effect of fetal cocaine exposure on newborn neurologic function

GABA system as the cause and effect in early development

GABA is the primary inhibitory neurotransmitter in the adult brain and through its actions on GABAARs, it protects against excitotoxicity and seizure activity, ensures temporal fidelity of neurotransmission, and regulates concerted rhythmic activity of neuronal populations. In the developing brain, the development of GABAergic neurons precedes that of glutamatergic neurons and the GABA system serves as a guide and framework for the development of other brain systems. Despite this early start, the maturation of the GABA system also continues well into the early postnatal period. In this review, we organize evidence around two scenarios based on the essential and protracted nature of GABA system development: 1) disruptions in the development of the GABA system can lead to large scale disruptions in other developmental processes (i.e., GABA as the cause), 2) protracted maturation of this system makes it vulnerable to the effects of developmental insults (i.e., GABA as the effect). While ample evidence supports the importance of GABA/GABAAR system in both scenarios, large gaps in existing knowledge prevent strong mechanistic conclusions.

Prenatal and Postnatal Cocaine Enhances the Induction and Expression of Locomotor Sensitization to Nicotine in Male Rats

INTRODUCTION

Several studies mention that early consumption of cannabis, alcohol, or even cocaine is related to an increase in the prevalence of daily consumption of tobacco in adulthood. However, other factors, such as genetic comorbidity, social influences, and even molecular, neurochemical, and behavioral alterations induced by prenatal and postnatal cocaine exposure, could also explain these observations, since these factors together increase the vulnerability of the offspring to the reinforcing effects of nicotine. The objective of this study was to determine the effect of prenatal and postnatal exposure to cocaine on nicotine-induced locomotor sensitization in young and adult rats.

AIMS AND METHODS

The study was divided into two stages: prenatal and postnatal. In the prenatal stage, a group of pregnant female Wistar rats was administered cocaine daily from day GD0 to GD21 (cocaine preexposure group), and another group of pregnant female rats was administered saline daily (saline preexposure group). Of the litters resulting from the cocaine preexposed and saline preexposed pregnant female groups, in the postnatal stage, only the male rats were used for the recording of the locomotor activity induced by different doses of nicotine (0.2, 0.4, and 0.6 mg/kg) during the induction and expression of locomotor sensitization at different postnatal ages (30, 60, 90, and 120 days).

RESULTS

Prenatal and postnatal cocaine exposure enhanced nicotine-induced locomotor activity and locomotor sensitization.

CONCLUSIONS

This suggests that prenatal and postnatal cocaine exposure can result in increased vulnerability to other drugs of abuse, such as nicotine, in humans.

IMPLICATIONS

Several studies have shown that the abuse of a drug, such as cannabis, alcohol, or even cocaine, at an early age can progress to more severe levels of use of other drugs, such as nicotine, to adulthood. Our data are consistent with this hypothesis, since prenatal and postnatal cocaine exposure enhanced the nicotine-induced increase in locomotor activity and locomotor sensitization. This suggests that prenatal and postnatal exposure to cocaine enhances the drug's salience.

The physical and developmental outcomes of children whose mothers are substance abusers: Analysis of associated factors and the impact of early intervention

Background/objectives

Maternal illicit drug use is associated with negative physical and developmental outcomes for their born children. We aim to find out the incidence of different developmental problems in a cohort of Chinese children born to drug-abusing mothers, compare the physical health and developmental outcomes of the subjects recruited in the Integrated Program to the Comprehensive Child Development Service (CCDS), and to study the potential factors on their associations.

Methods

A retrospective longitudinal cohort study with frequent clinical assessments of the children's physical and developmental outcomes in a HKSAR's regional hospital from birth until 5 years old. 123 Children in Integrated Program were compared with 214 children in CCDS between 1 January 2008 and 28 February 2019. Cox regression analysis was performed to determine the possible factors associated with the developmental outcomes.

Results

Developmental delay was detected in 129 children (38.9%). CCDS group has significantly higher incidence of cognitive delay (p = < 0.001), language delay (p = < 0.001), motor delay (p = < 0.001), social delay (p = 0.002), and global delay (p = 0.002). On Cox multivariable regression analysis, integrated program (HRadj 0.53, 95% C. I. 0.34-0.84), social support (HRadj 0.45, 95% C.I. 0.25-0.80), and maternal abstinence from drug use up to 2-year post-delivery (HRadj 0.62, 95% C.I. 0.40-0.95) were significant protective factors, while male gender (HRadj 1.73, 95% C.I. 1.18-2.54) was a significant risk factor.

Conclusion

CCDS achieves early engagement of drug-abusing expectant mothers during pregnancy, and an early integrated program with multidisciplinary collaboration was an independent factor in improving the developmental outcomes of these vulnerable children.

Infants of Mothers with Cocaine Use: Review of Clinical and Medico-Legal Aspects

Illicit drug use is a global problem that also affects pregnant women. Substance use and alcohol abuse during pregnancy may have various harmful consequences for both mothers and foetuses. Intrauterine exposure to illicit substances can be investigated through maternal reports and toxicological tests on mothers' and/or newborns' samples. While the negative effects of alcohol and opioid use on pregnancy, the foetus, and/or newborn are well established, the effects of cocaine use remain controversial. We performed a review of the literature to evaluate the current state of knowledge of the effects of intrauterine cocaine exposure on newborns' and children's long-term development and to highlight possible implications for health professionals dealing with women who use cocaine during pregnancy. Although intrauterine cocaine exposure has been associated with reduced infant measurements, no specific amount of cocaine use exerting such effects has been determined, and no long-term effects have been confirmed. The evidence of cocaine use during pregnancy justifies a clinical and social takeover of the mother and newborn without assuming that there will certainly be long-term damage related to intrauterine cocaine exposure, but also considering other possible associated factors.

Prenatal drug exposure and executive function in early adolescence

PURPOSE

Study of the relationship between prenatal cocaine exposure (PCE) and executive function (EF) has yielded inconsistent results. The purpose of the current study is to examine whether PCE, biological sex, environmental risk, and their interaction predicted EF in early adolescence.

METHODS

135 12-year-old adolescents (40.7% with PCE), who were followed prospectively from birth, attempted up to 8 Tower of Hanoi (ToH) puzzle trials of increasing complexity. The number of correctly completed puzzles served as the main outcome measure. Survival analysis was used to examine predictors of the number of successfully completed trials.

RESULTS

As trial difficulty increased, fewer adolescents were able to solve the TOH puzzle. Adolescents from high risk environments and with either prenatal alcohol or prenatal cannabis exposure completed fewer puzzles (p < .05). In addition, a hypothesized 3-way interaction of PCE x sex x environmental risk was found such that cocaine-exposed males with high environmental risk had the worst performance (p < .01).

CONCLUSIONS

The current findings are consistent with prior research indicating that males with PCE may be at particular risk of poorer functioning and highlight the potential importance of examining adolescent's sex and environmental risk as moderators of PCE effects.

Prenatal and postnatal cocaine exposure enhances the induction and expression of locomotor sensitization to cocaine in rats

Prenatal and postnatal exposure to cocaine can affect the development and function of the central nervous system in offspring. It also produces changes in cocaine-induced dopamine release and increases cocaine self-administration and cocaine-induced conditioned place preference. Further, prenatal cocaine exposure involves greater risk for development of a substance use disorder in adolescents. Therefore, the objective of this study was to determine the effect of prenatal and postnatal cocaine exposure on locomotor sensitization in rats. A group of pregnant female Wistar rats were administered daily from day GD0 to GD21 with cocaine (cocaine pre-exposure group) and another group pregnant female rats were administered daily with saline (saline pre-exposure group). During lactation (PND0 to PND21) pregnant rats also received cocaine administration or saline, respectively. Of the litters resulting of the cocaine pre-exposed and saline pre-exposed pregnant female groups, only the male rats were used for the recording of the locomotor activity induced by different doses of cocaine (1, 5, 10, 20 and 40 mg/Kg/day) during the induction and expression of locomotor sensitization at different postnatal ages (30, 60, 90 and 120 days), representative of adolescence and adult ages. The study found that prenatal and postnatal cocaine exposure enhanced locomotor activity and locomotor sensitization, and such increase was dose- and age-dependent. This suggests that prenatal and postnatal cocaine exposure can result in increased vulnerability to cocaine abuse in young and adult humans.

The cellular basis of fetal endoplasmic reticulum stress and oxidative stress in drug-induced neurodevelopmental deficits

Prenatal substance exposure is a growing public health concern worldwide. Although the opioid crisis remains one of the most prevalent addiction problems in our society, abuse of cocaine, methamphetamines, and other illicit drugs, particularly amongst pregnant women, are nonetheless significant and widespread. Evidence demonstrates prenatal drug exposure can affect fetal brain development and thus can have long-lasting impact on neurobehavioral and cognitive performance later in life. In this review, we highlight research examining the most prevalent drugs of abuse and their effects on brain development with a focus on endoplasmic reticulum stress and oxidative stress signaling pathways. A thorough exploration of drug-induced cellular stress mechanisms during prenatal brain development may provide insight into therapeutic interventions to combat effects of prenatal drug exposure.

Prenatal exposure: The effects of prenatal cocaine and methamphetamine exposure on the developing child

Prenatal substance use remains a significant issue in the United States. Initial reports regarding prenatal cocaine and methamphetamine exposure suggested profound adverse effects on child development. However, subsequent prospective, longitudinal investigations have found more subtle effects. What follows is a brief review of the health, growth, behavioral, and intellectual outcomes for children exposed to prenatal cocaine and prenatal methamphetamine. Factors that may mitigate or intensify subtle adverse effects manifested in exposed children will also be discussed. Birth Defects Research (Part C) 108:142-146, 2016. © 2016 Wiley Periodicals, Inc.

3D brain Organoids derived from pluripotent stem cells: promising experimental models for brain development and neurodegenerative disorders

Three-dimensional (3D) brain organoids derived from human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), appear to recapitulate the brain's 3D cytoarchitectural arrangement and provide new opportunities to explore disease pathogenesis in the human brain. Human iPSC (hiPSC) reprogramming methods, combined with 3D brain organoid tools, may allow patient-derived organoids to serve as a preclinical platform to bridge the translational gap between animal models and human clinical trials. Studies using patient-derived brain organoids have already revealed novel insights into molecular and genetic mechanisms of certain complex human neurological disorders such as microcephaly, autism, and Alzheimer's disease. Furthermore, the combination of hiPSC technology and small-molecule high-throughput screening (HTS) facilitates the development of novel pharmacotherapeutic strategies, while transcriptome sequencing enables the transcriptional profiling of patient-derived brain organoids. Finally, the addition of CRISPR/Cas9 genome editing provides incredible potential for personalized cell replacement therapy with genetically corrected hiPSCs. This review describes the history and current state of 3D brain organoid differentiation strategies, a survey of applications of organoids towards studies of neurodevelopmental and neurodegenerative disorders, and the challenges associated with their use as in vitro models of neurological disorders.

Extrinsic Barriers to Substance Abuse Treatment among Pregnant Drug Dependent Women

The objective of this qualitative study was to examine extrinsic barriers to substance abuse treatment among pregnant and parenting women enrolled in residential perinatal substance abuse treatment programs in Northern California. Life history interviews were conducted with 36 women to examine help-seeking behaviors before treatment enrollment. Data analysis used the analytic framework of Mandelbaum (1973) to describe dimensions, turnings, and adaptations of participants. Results indicated that the majority (n = 34) of participants sought prenatal care but identified fear of punitive actions from helping institutions and individuals as a major barrier. Other extrinsic barriers included substance abuse treatment program barriers, partners, the status of opiate dependency, and the status of pregnancy. Biological, socio-cultural, and psychosocial dimensions of participants' care-seeking experiences were identified. The turning was pregnancy and adaptations included preserving the family, managing fear and manifesting faith. Findings describe the transformation of the therapeutic alliance and the gendered impact of two decades of the War on Drugs in the United States. Participants' coping strategies suggest that the desire for child custody and concern for fetal and child well-being was a priority and motivated care seeking despite extrinsic barriers perceived to be threatening to the woman's safety and autonomy.

Neurobehavioral and Developmental Traiectories Associated with Level of Prenatal Cocaine Exposure

INTRODUCTION

In experimental models, prenatal cocaine exposure has been found to perturb GABA and dopamine development. Clinically, abnormalities in tone, posture and state regulation are noted in early infancy but the evolution of these findings over time is not well described. The current study assesses the longitudinal effects of prenatal cocaine exposure in dose-dependent fashion on developmental & behavioral and neurological trajectories over the first 2 years of life.

METHODS

Three hundred and eighty infants, 113 cocaine-exposed, were enrolled at birth from an urban hospital from 2000 to 2004. Exposure was determined by maternal interview, segmental hair analyses (RIAH^™) in all, and meconium and urine in a subset. Developmental, behavioral and neurological assessments were carried out blind to drug exposure at 6, 12 and 24 months of age in the 306 children who returned in follow-up. Mixed-effects linear modeling (developmental growth curve) assessed change in outcome over time.

RESULTS

The mental developmental growth curve showed a negative slope (2.2 points) in adjusted analyses among cocaine-exposed children over the first 2 years of life. (p=.04), while the slope of the motor development growth curve did not. Adjusting for microcephaly at 6 months diminished the strength of the association between cocaine exposure and mental developmental growth curve (effect modification). Cocaine exposure was marginally associated with behavioral outcomes in adjusted analyses. Total Behavior scores and Orientation/Engagement scores improved with age. At 1 year of age, prenatal cocaine exposure was significantly associated with lower motor development scores. High rates of hypertonia (global and diparesis) identified at the 6-month visit dropped dramatically in the first 2 years of life: cocaine-exposed children showed a more rapid rate of resolution of hypertonia than unexposed children, with hypertonia improving 2.2 times faster among those with heavy cocaine exposure.

CONCLUSION

We found differences in mental performance over the first 2 years of life associated with prenatal cocaine exposure that was mediated by microcephaly implying that cocaine exerts a sustained teratogenic effect on brain development. Early neurological (hypertonia) and behavioral findings associated with prenatal cocaine exposure improved over time. Hypertonia did not predict long-term development impairments. Conceivably, the transient nature of neurobehavioral manifestations reflects postnatally a tendency towards homeostasis of cocaine-related embryopathic perturbations of GABA and dopaminergic systems.

Gene expression profiling reveals distinct cocaine-responsive genes in human fetal CNS cell types

OBJECTIVES

Prenatal exposure to cocaine causes cytoarchitectural alterations in the developing neocortex. Previously, we reported that cocaine inhibits neural progenitor cell proliferation through oxidative endoplasmic reticulum stress and consequent down-regulation of cyclin A, whereas cyclin A expression was increased in astrocytes. In the present study, cell type-specific responses to cocaine were further explored.

METHODS

Gene expression profiles were examined in five types of cells obtained from the human fetal cerebral cortex at 20 weeks gestation. Cells were treated with 100 µM cocaine in vitro for 24 hr, followed by gene expression analysis using a human neural/stem cell/drug abuse-focused cDNA array, with verification by quantitative real-time RT-PCR.

RESULTS

Cocaine influenced transcription of distinct categories of genes in a cell type-specific manner. Cocaine down-regulated cytoskeleton-related genes including ezrin, γ2 actin, α3d tubulin and α8 tubulin in neural and/or A2B5+ progenitor cells. In contrast, cocaine modulated immune and cell death-related genes in microglia and astrocytes. In microglia, cocaine up-regulated the immunoregulatory and pro-apoptotic genes IL-1β and BAX. In astrocytes, cocaine down-regulated the immune response gene glucocorticoid receptor and up-regulated the anti-apoptotic genes 14-3-3 ε and HVEM. Therefore, cell types comprising the developing neocortex show differential responses to cocaine.

CONCLUSIONS

These data suggest that cocaine causes cytoskeletal abnormalities leading to disturbances in neural differentiation and migration in progenitor cells, while altering immune and apoptotic responses in glia. Understanding the mechanisms of cocaine's effects on human CNS cells may help in the development of therapeutic strategies to prevent or ameliorate cocaine-induced impairments in fetal brain development.

Prenatal Cocaine Disrupts Serotonin Signaling-Dependent Behaviors: Implications for Sex Differences, Early Stress and Prenatal SSRI Exposure

Prenatal cocaine (PC) exposure negatively impacts the developing nervous system, including numerous changes in serotonergic signaling. Cocaine, a competitive antagonist of the serotonin transporter, similar to selective serotonin reuptake inhibitors (SSRIs), also blocks dopamine and norepinephrine transporters, leaving the direct mechanism through which cocaine disrupts the developing serotonin system unclear. In order to understand the role of the serotonin transporter in cocaine's effect on the serotonergic system, we compare reports concerning PC and prenatal antidepressant exposure and conclude that PC exposure affects many facets of serotonergic signaling (serotonin levels, receptors, transporters) and that these effects differ significantly from what is observed following prenatal SSRI exposure. Alterations in serotonergic signaling are dependent on timing of exposure, test regimens, and sex. Following PC exposure, behavioral disturbances are observed in attention, emotional behavior and stress response, aggression, social behavior, communication, and like changes in serotonergic signaling, these effects depend on sex, age and developmental exposure. Vulnerability to the effects of PC exposure can be mediated by several factors, including allelic variance in serotonergic signaling genes, being male (although fewer studies have investigated female offspring), and experiencing the adverse early environments that are commonly coincident with maternal drug use. Early environmental stress results in disruptions in serotonergic signaling analogous to those observed with PC exposure and these may interact to produce greater behavioral effects observed in children of drug-abusing mothers. We conclude that based on past evidence, future studies should put a greater emphasis on including females and monitoring environmental factors when studying the impact of PC exposure.

Nonepileptic motor phenomena in the neonate

The newborn infant is prone to clinical motor phenomena that are not epileptic in nature. These include tremors, jitteriness, various forms of myoclonus and brainstem release phenomena. They are frequently misdiagnosed as seizures, resulting in unnecessary investigations and treatment with anticonvulsants, which have potentially harmful side effects. Unfortunately, there is a paucity of literature about many of these phenomena in the newborn, and some of the major textbooks refer to these events as nonepileptic seizures, leading to further confusion for the practitioner. The present paper aims to review these phenomena with special emphasis on differentiating them from epileptic seizures, and offers information on treatment and prognosis wherever possible.

Cocaine causes deficits in radial migration and alters the distribution of glutamate and GABA neurons in the developing rat cerebral cortex

Prenatal cocaine exposure induces cytoarchitectural changes in the embryonic neocortex; however, the biological mechanisms and type of cortical neurons involved in these changes are not known. Previously, we found that neural progenitor proliferation in the neocortical ventricular zone (VZ) is inhibited by cocaine; here, we examine the changes in cortical neurogenesis and migration of glutamate and GABA neurons induced by prenatal cocaine exposure. Pregnant rats received 20 mg/kg of cocaine intraperitoneally twice at an interval of 12 h during three periods of neocortical neurogenesis. Neocortical area and distribution of developing neurons were examined by counting Tuj1+, glutamate+, or GABA+ cells in different areas of the cerebral cortex. Cocaine decreased neocortical area by reducing the size of the Tuj1+ layer, but only when administered during early periods of neocortical neurogenesis. The number of glutamatergic neurons was increased in the VZ but was decreased in the outer cortical laminae. Although the number of GABA+ neurons in the VZ of both the neocortex and ganglionic eminences was unchanged, GABA+ cells decreased in all other neocortical laminae. Tangential migration of GABA+ cells was also disrupted by cocaine. These findings suggest that in utero cocaine exposure disturbs radial migration of neocortical neurons, possibly because of decreased radial glia guiding support through enhanced differentiation of neocortical VZ progenitors. Cocaine interrupts radial migration of both glutamatergic and GABAergic neurons within the neocortex, in addition to the tangential migration of GABAergic neurons from the subcortical telecephalon. This may result in abnormal neocortical cytoarchitecture and concomitant adverse functional effects.

Potential latent effects of prenatal cocaine exposure on growth and the risk of cardiovascular and metabolic disease in childhood

The literature strongly suggests that prenatal exposure to certain medications and substances does not cause major malformations in early childhood. However, these exposures may have far-reaching latent health effects, such as restricted growth, hypertension, and cardiovascular events in adulthood. We reviewed the literature to identify the effects of prenatal cocaine exposure on growth and the risk of cardiovascular and metabolic disease in late adolescence and early adulthood by examining studies that were published in peer-reviewed English-language journals from 1990 through 2009 and indexed in MEDLINE. We found that animal and clinical studies of the influence of prenatal cocaine exposure on child and adolescent growth and the subsequent development of myocardial and cardiometabolic disease risk factors are few and inconclusive. Studies support the hypothesis that vascular and hemodynamic functions are partially programmed in early life and thus substantially influence vascular aging and arterial stiffening in later life. Sub-optimal fetal nutrition and growth may increase blood pressure and the development of cardiovascular and metabolic disease in late life. How prenatal cocaine and other drug exposure effects this relationship is currently unknown. Despite high rates of cocaine and other drug use during pregnancy (up to 18% in some studies), little is known about the health effects of prenatal cocaine exposure in adolescence and early adulthood. The few studies of early growth deficits persisting into adolescence are inconclusive. The literature provides little information on how exposed children grow into adulthood and about their subsequent risk of cardiometabolic and vascular disease.

Infant race affects application of clinical guidelines when screening for drugs of abuse in newborns

BACKGROUND

Screening for illicit drugs in newborns has privacy, social, and legal risks for families of the infants. Established drug-screening criteria may be applied in a manner that considers nonproven risk factors such as race in addition to evidence-based factors.

OBJECTIVE

The goal of this study was to determine if race was used as a criterion for screening infants for intrauterine cocaine exposure. We hypothesized that infants of black mothers would be more likely to be screened regardless of whether they met the standard criteria for screening of our institution's NICU.

METHODS

We used the electronic medical records of newborn infants and their mothers to determine which mother-infant pairs had documented evidence of meeting the criteria for screening infants for prenatal exposure to illicit drugs set forth in the guidelines of our NICU. We then assessed the rates of drug screening to determine the strongest predictors of whether an infant would be screened.

RESULTS

We assessed 2121 mother-infant pairs. Infants born to black mothers were more likely than those born to white mothers to have screening performed whether they met screening criteria (35.1% vs 12.9%; P < .001) or did not (5.3% vs 1.2%; P < .001). In a logistic regression analysis, black race remained independently associated (odds ratio: 2.17 [95% confidence interval: 1.25-3.79]) with drug screening even when we controlled for our standard screening criteria and income, insurance status, and maternal education.

CONCLUSION

Providers seemed to have used race, in addition to recognized risk criteria, as a factor in deciding whether to screen an infant for maternal illicit drug use.

Maternal methadone dose during pregnancy and infant clinical outcome

In recent decades there has been an increase in the methadone dosages prescribed for opioid dependent women during pregnancy. Using prospective longitudinal data from a cohort of 32 methadone exposed and 42 non-methadone exposed infants, this study examined the relationship between maternal methadone dose during pregnancy and a range of infant clinical outcomes. Of particular interest was the extent to which any observed associations might reflect the direct causal effects of maternal methadone dose and/or the confounding effects of adverse maternal lifestyle factors correlated with methadone use during pregnancy. Findings revealed the presence of clear linear relationships between the mean methadone dose prescribed for mothers during pregnancy and a range of adverse infant clinical outcomes. With increasing maternal methadone dose there was a corresponding increase in infants' risk of being born preterm, being symmetrically smaller, spending longer periods in hospital and the need for treatment for Neonatal Abstinence Syndrome. After due allowance for potentially confounding maternal health and lifestyle factors, maternal methadone dose during pregnancy remained a significant predictor of preterm birth, growth, and the duration of infant hospitalization post delivery. These findings suggest a need to examine more closely the potential impacts of recent trends towards the use of higher methadone dose levels during pregnancy.

Executive functioning at ages 5 and 7 years in children with prenatal cocaine exposure

This prospective longitudinal study evaluated the effect of prenatal cocaine exposure (PCE) on executive functioning in 5- and 7-year-old children. In total, 154 pregnant cocaine users, identified by urine toxicology and structured interviews, were matched to 154 nonusers. Children were assessed by certified masked evaluators, and caregivers were interviewed by experienced staff during home visits. In approximately 90% of the surviving sample tested at ages 5 and 7 years, structural equation modeling demonstrated that an increased head circumference at birth (adjusted for gestation) significantly predicted better performance on executive functioning, and that PCE was indirectly related to executive functioning through its significant negative effect on head circumference at birth. At age 5 years, quality of environment also predicted executive functioning, and the R(2) for the total model was 0.24. At 7 years, caregiver functioning predicted quality of environment, which in turn was positively related to executive functioning, and girls had better executive functioning. The total model at age 7 years accounted for 30% of the variance in executive functioning.

Neonatal Hypertonia: II. differential diagnosis and proposed neuroprotection

More accurate documentation of a neonate's specific hypertonic state could be helpful as part of serial neurologic examinations. The clinician would then be in a more advantageous position to choose the appropriate neuroprotective drug or the procedure that best fits with the etiology, localization, and timing of injury. Ideally, choices for neuroprotection will integrate history, examination, and diagnostic findings before considering options for prophylaxis, neurorescue, or neurorepair. Measuring the efficacy of a neuroprotection protocol should include a complete list of life-course challenges, including motor, epileptic, cognitive, and behavioral outcomes as expressed at successively older ages.

A mechanism for the inhibition of neural progenitor cell proliferation by cocaine

BACKGROUND

Prenatal exposure of the developing brain to cocaine causes morphological and behavioral abnormalities. Recent studies indicate that cocaine-induced proliferation inhibition and/or apoptosis in neural progenitor cells may play a pivotal role in causing these abnormalities. To understand the molecular mechanism through which cocaine inhibits cell proliferation in neural progenitors, we sought to identify the molecules that are responsible for mediating the effect of cocaine on cell cycle regulation.

METHODS AND FINDINGS

Microarray analysis followed by quantitative real-time reverse transcription PCR was used to screen cocaine-responsive and cell cycle-related genes in a neural progenitor cell line where cocaine exposure caused a robust anti-proliferative effect by interfering with the G1-to-S transition. Cyclin A2, among genes related to the G1-to-S cell cycle transition, was most strongly down-regulated by cocaine. Down-regulation of cyclin A was also found in cocaine-treated human primary neural and A2B5+ progenitor cells, as well as in rat fetal brains exposed to cocaine in utero. Reversing cyclin A down-regulation by gene transfer counteracted the proliferation inhibition caused by cocaine. Further, we found that cocaine-induced accumulation of reactive oxygen species, which involves N-oxidation of cocaine via cytochrome P450, promotes cyclin A down-regulation by causing an endoplasmic reticulum (ER) stress response, as indicated by increased phosphorylation of eIF2alpha and expression of ATF4. In the developing rat brain, the P450 inhibitor cimetidine counteracted cocaine-induced inhibition of neural progenitor cell proliferation as well as down-regulation of cyclin A.

CONCLUSIONS

Our results demonstrate that down-regulation of cyclin A underlies cocaine-induced proliferation inhibition in neural progenitors. The down-regulation of cyclin A is initiated by N-oxidative metabolism of cocaine and consequent ER stress. Inhibition of cocaine N-oxidative metabolism by P450 inhibitors may provide a preventive strategy for counteracting the adverse effects of cocaine on fetal brain development.

Augmented D1 dopamine receptor signaling and immediate-early gene induction in adult striatum after prenatal cocaine

BACKGROUND

Prenatal exposure to cocaine can impede normal brain development, triggering a range of neuroanatomical and behavioral anomalies that are evident throughout life. Mouse models have been especially helpful in delineating neuro-teratogenic consequences after prenatal exposure to cocaine. The present study employed a mouse model to investigate alterations in D(1) dopamine receptor signaling and downstream immediate-early gene induction in the striatum of mice exposed to cocaine in utero.

METHODS

Basal, forskolin-, and D(1) receptor agonist-induced cyclic adenosine monophosphate (cAMP) levels were measured ex vivo in the adult male striatum in mice exposed to cocaine in utero. Further studies assessed cocaine-induced zif 268 and homer 1 expression in the striatum of juvenile (P15), adolescent (P36), and adult (P60) male mice.

RESULTS

The D(1) dopamine receptor agonist SKF82958 induced significantly higher levels of cAMP in adult male mice treated with cocaine in utero compared with saline control subjects. No effects of the prenatal treatment were found for cAMP formation induced by forskolin. After an acute cocaine challenge (15 mg/kg, IP), these mice showed greater induction of zif 268 and homer 1, an effect that was most robust in the medial part of the mid-level striatum and became more pronounced with increasing age.

CONCLUSIONS

Together these findings indicate abnormally enhanced D(1) receptor signal transduction in adult mice after prenatal cocaine exposure. Such changes in dopamine receptor signaling might underlie aspects of long-lasting neuro-teratogenic effects evident in some humans after in utero exposure to cocaine and identify the striatum as one target potentially vulnerable to gestational cocaine exposure.

Illicit drug use and neonatal outcomes: a critical review

Although the neonatal consequences of tobacco and alcohol exposure are well established, the evidence related to prenatal illicit drug use is less consistent despite prevalent views to the contrary. The many social, psychosocial, behavioral, and biomedical risk factors for adverse birth outcomes associated with illicit drug use complicate the evaluation of neonatal effects. Placing emphasis on recent research, this review summarizes the epidemiologic literature on the neonatal impact of marijuana, opiate, and cocaine use. Of these drugs, cocaine use is most consistently related to fetal growth decrements and dose-response effects have been observed. However, studies to date have largely failed to control for associated social, psychosocial, and contextual factors. Additional recommendations for future research are provided. It is likely that interventions will need to address the factors surrounding drug use to greatly improve neonatal outcomes (e.g., social circumstances, poor nutrition, stress, infections).

Rats exposed to cocaine during late gestation and early postnatal life show deficits in hippocampal pyramidal and granule cells in later life

In humans, the offspring of maternal cocaine misusers are known to have subtle cognitive and motor impairments in later life. It was therefore hypothesized that such exposure in animals would also affect the morphological structure of the brain. This possibility was investigated by exposing rats to cocaine between embryonic day 15 and postnatal day 6. Samples of the cocaine-exposed and control rats were killed for examination at 22 and 150 postnatal days of age. Stereological procedures (the Cavalieri principle together with the physical disector method) were utilized to estimate the total number of pyramidal and granule cells in defined regions of the hippocampal formation. At 22 days of age, the control offspring had about 373 000 pyramidal cells whereas the cocaine-treated animals only had about 310,000 cells in the CA1 + CA2 + CA3 region. By 150 days of age the values were about 396,000 and 348,000, respectively. The differences between age-matched groups were statistically significant. There were about 626,000 and 687,000 dentate gyrus granule cells in the 22-day-old control and cocaine-treated groups, respectively. By postnatal day 150 the control rats had about 832,000 granule cells whilst the cocaine-treated rats had about 693,000. There was a significant main effect of age as well as group-age interaction in this measure. These results show that even moderate exposure to cocaine during the late gestation and early postnatal period in rats is a potent teratogen and can markedly influence the development of neurons in the hippocampal formation.

Developmental outcome in children with intrauterine exposure to substances

The developmental outcome of children born to Swiss substance-dependent mothers in a residential treatment program was studied in a sample of 61 children ranging from infancy to preadolescence (mean age = 5.10, SD = 3.10 years) by use of age-appropriate tests of intelligence. A large list of biological and psychosocial risk factors was tested for associations with outcome in the children. The mean profile of test findings across all age ranges was significantly lower than population norms and there was an excess of children with subnormal intellectual functioning. Performance IQ was associated negatively only with intrauterine substance exposure, but with none of the other risk factors. Among the various substances, predominantly heroin or methadone were responsible for this association when controls for nicotine or cannabis consumption were made. The study provides further evidence that intrauterine exposure to heroin and methadone negatively affects the developmental outcome in the offspring of substance-dependent mothers.

Prenatal cocaine exposures and dose-related cocaine effects on infant tone and behavior

BACKGROUND

In experimental models, prenatal cocaine exposure has been found to perturb monoaminergic development. In humans, numerous studies have sought clinical correlates, but few have focused on dose-related effects, especially as regards neurologic function beyond the neonatal period.

OBJECTIVE

To assess whether prenatal cocaine exposure has adverse effects on infant neurologic, developmental and behavioral outcomes and whether any effects are dose-dependent.

DESIGN/METHODS

Infants (398) were enrolled at birth from an urban hospital. Drug exposure was ascertained with biomarkers in hair (n=395), urine (n=170) and meconium (n=109). Children were followed prospectively and 286 (72%) were evaluated blind to drug exposure at 6 months of age with the Bayley scales, Fagan Scale of Infant Intelligence and a standardized neurological examination.

RESULTS

Certain neurological findings increased significantly by the amount of cocaine detected in maternal hair, e.g. abnormality of tone, as indicated by extensor posture was detected among 28% of cocaine-unexposed infants, 43% of infants exposed to lower and 48% exposed to higher cocaine levels in maternal hair (p<0.009). Persistent fisting increased in a similar dose-dependent manner. These associations persisted in adjusted analyses. Prenatal cocaine exposure was not associated with developmental scores (mental, motor or novelty preference) but was associated with lower orientation scores in adjusted analyses.

CONCLUSIONS

At 6 months of age, prenatal cocaine exposure was associated with abnormalities of tone and posture and with lower orientation scores. Perturbations in monoaminergic systems by cocaine exposure during fetal development may explain the observed neurological and behavioral symptoms. Whether such findings in infancy increase the risk of later neurobehavioral problems requires further study.

Effects of prenatal cocaine, morphine, or both on postnatal opioid (μ) receptor development

We studied the effects of prenatal cocaine and morphine given separately and in combination on the (1) postnatal brain mu-opioid receptor development and (2) interaction of dopamine with mu receptors. Pregnant rats received single daily intraperitoneal (I.P.) injections of saline, cocaine (20 mg/kg), morphine (2 mg/kg), or the combination of both drugs from day 13 to day 20 of gestation. Postnatal days (P) 1, 7, 14, and 28, whole brains were analyzed for opioid receptor binding and mu mRNA. Prenatal cocaine administered by itself had no significant effect on the ontogeny of brain mu receptors on all the days studied when compared to controls. The morphine-treated group showed a significant increase in mu receptor binding on P1 and P7. Exposure to both cocaine and morphine showed a significant increase in mu receptor density on P1 and P7. In addition, there was also a significant increase in MOR mRNA in both the morphine alone and combination groups. Pretreatment with dopamine D2 receptor antagonist (sulpiride, 20 mg/kg) prior to drug administration showed decreased mu receptor binding on P1 and P7. These results suggest that prenatal exposure to morphine or a combination of cocaine and morphine significantly increases mu receptor density. By P14, mu-opioid receptor binding was no longer different than the control. This may suggest that the effect on receptor may be short-lived and that other key intracellular events may be activated to mediate the long-term effects. Also, the data show that dopaminergic mechanisms are (or opioid-dopamine interaction is) involved in the effects of morphine alone or morphine in combination with cocaine on mu receptor regulation.

Prenatal alcohol and drug exposures in adoption

Prenatal alcohol and drug exposures are a significant concern in many domestic and international adoptions. This article addresses the following substance exposures for children: alcohol, opiates, tobacco, marijuana, cocaine, and methamphetamines. For each substance, we review the teratogenicity of the exposure and identify the spectrum of neurodevelopmental issues that can present in children exposed to this substance. Diagnosis of the spectrum of fetal alcohol outcomes is also discussed. When possible, we provide country-specific statistics on exposure risks for adopted children.

Augmented Constitutive CREB Expression in the Nucleus accumbens and Striatum May Contribute to the Altered Behavioral Response to Cocaine of Adult Mice Exposed to Cocaine in utero

Neuroadaptations occurring in the mesolimbic dopamine pathway following recurrent exposure to drugs of abuse have been correlated with a behavioral phenomenon known as behavioral sensitization. We have developed an animal model of prenatal cocaine exposure and, using a postnatal sensitization protocol, have examined the subsequent sensitivity of offspring to cocaine. Pregnant Swiss Webster dams were injected twice daily from embryonic day 8 to 17, inclusive, with cocaine (COC40: administered cocaine HCl at a dose of 40 mg/kg/day, and COC20: administered cocaine HCl at a dose of 20 mg/kg/day), or saline (SAL). The SPF40 group (saline pair-fed), a nutritional control group, was 'pair-fed' with COC40 dams. Activity was recorded for 30 min during a 3-day saline habituation, a 14-day 'initiation' phase, when animals received cocaine (15 mg/kg) or saline every other day, and following a 21-day 'withdrawal' period when all mice were challenged with cocaine. COC40 offspring, as compared with SAL controls, did not habituate to a novel environment, demonstrated increased cocaine-induced stereotypy on Coc 1 (first cocaine injection), and blunted locomotor sensitization on challenge as measured by the percentage of each animal's baseline locomotion. Tissue samples of the nucleus accumbens (NAc) and striatum (Str) of all four prenatal treatment groups were examined to determine whether alterations in the transcription factor CREB or glutamate receptor subunit, GluR1, induced by prenatal cocaine treatment may have contributed to the altered behavioral responses. Immunoblot quantitation revealed significantly increased constitutive CREB expression in the NAc and Str of COC40 mice as compared with SAL controls. Such alterations in constitutive CREB levels may contribute to some of the behavioral differences reported in adult mice exposed to cocaine in utero.

Methadone maintenance program in pregnancy in a Swiss perinatal center (II): neonatal outcome and social resources

BACKGROUND

The aim of the study was to analyze the neonatal impact of a methadone maintenance program in pregnancy, and the social resources of the families involved.

METHODS

Descriptive analysis of neonatal data in live births after 24 weeks of gestation in pregnant women enrolled in a methadone maintenance program. The data of 86 babies were analyzed.

RESULTS

Median gestational age was 38 (0)/(7) (31-41) weeks; 21 babies (24%) were premature. Median birthweight was 2662 (1340-4050) g; 27% of babies were growth retarded (<3rd centile), and 13% had microcephaly (<3rd centile). Sixty-two percent developed abstinence syndrome requiring pharmacological treatment for a median 47 days. Child Protective Services (CPS) were involved in 56% of cases, and 42% of newborns required placement outside the mother's home.

CONCLUSIONS

Babies born to women on methadone had a fourfold higher incidence of prematurity, a ninefold higher incidence of intrauterine growth retardation (IUGR), and a fourfold higher incidence of microcephaly compared with the normal population. Sixty-two percent required pharmacological treatment for abstinence syndrome and 42% required placement.

Neurological and developmental outcomes of prenatally cocaine-exposed offspring from 12 to 36 months

Second generation studies of prenatal cocaine exposure failed to find gross deficits after controlling for confounders. Concern remained that exposure could cause subtle deficits. This prospective, cohort study evaluated effects of cocaine on development at 12, 18, 24, and 36 months. From 1991-1993, 361 mother-infant pairs were recruited from the Children's Hospital of New York, Presbyterian Medical Center's prenatal clinic or delivery room suite. Mothers were assigned to the cocaine group based on report of prenatal cocaine use or positive urine toxicology. Control mothers were enrolled from the same clinic and matched for age and socioeconomic status (SES). Women with serious medical problems were excluded from either group. Of the retained cohort, at 12 months, 147 infants were exposed and 89 were unexposed case controls. Both groups were raised in impoverished environments with few supports. Developmental evaluations were conducted blinded to group. Cross-sectional analysis revealed cocaine-related deficits in neurological exams and speech across all time periods, in spite of catch up in weight, length, and head circumference. Overall analysis of development was evaluated using Generalized Estimating Equations regression analysis. Bayley Mental [Badj = -6.5 (CI--9.4, -3.5, p < or = 0.001)] and Psychomotor [Badj = -3.9 (CI--7.4, -0.5, p = 0.02)] Developmental Indices showed deficits after controlling for confounders. Males were more vulnerable to cocaine exposure for height, motor development, and emotional regulation. Dose-response relationships existed for abnormal neurological exams (Ptrends < 0.08), Mental Development Index (MDI) (Ptrend < 0.001), and Psychomotor Development Index (PDI) (Ptrend < 0.001) deficits. Although nonexposed children performed poorly, cocaine-exposed children showed worse performance. Both groups showed declines at 18 months in mental and psychomotor development from which only nonexposed children rebounded. Overall, cocaine exposure adds an additional risk to disadvantaged children's development. Cocaine-exposed children are less resilient to effects of these multiple risks.

Association between patterns of maternal substance use and infant birth weight, length, and head circumference

OBJECTIVE

To determine the effects of patterns of drug use during term pregnancy on infant growth parameters at birth.

METHODS

Histories of cocaine, opiate, alcohol, tobacco, and marijuana use during the 3-month period before pregnancy and the 3 trimesters of pregnancy were recorded at the infants' 1-month visit. Patterns of use were categorized as consistently high, moderate, or low/none or increasing/decreasing, and effects on growth parameters were analyzed in multivariate linear regression analyses, with adjustment for clinical site, maternal age, prepregnancy weight, multidrug use, and socioeconomic status.

RESULTS

A total of 241 cocaine-exposed women and 410 non-cocaine-exposed women participated in the study. In the cocaine-exposed group, 75% used alcohol, 90% used tobacco, and 53% used marijuana; in the non-cocaine-exposed group, 57% used alcohol, 34% used tobacco, and 19% used marijuana. Birth weight, birth length, and head circumference were significantly greater among infants born to women who used no drugs, compared with women with any cocaine, opiate, alcohol, tobacco, or marijuana use, and were greater among infants born to cocaine nonusers, compared with cocaine users. With adjustment for confounders, birth weight was significantly affected by cocaine (deficit of 250 g with consistently low pattern) and tobacco (deficits of 232 g with consistently high pattern, 173 g with consistently moderate pattern, 153 g with decreasing pattern, and 103 g with consistently low pattern). Head size was affected by cocaine (deficit of 0.98 cm with consistently moderate pattern) and tobacco (deficits of 0.72 cm with consistently high pattern and 0.89 cm with consistently moderate pattern). Birth length was affected by tobacco use only (deficits of 0.82 cm with consistently high pattern and 0.98 cm with decreasing use).

CONCLUSION

Patterns of tobacco use during pregnancy affect birth weight, length, and head circumference, whereas cocaine affects birth weight and head size, when adjustments are made for confounders, including multidrug use.

Abnormal auditory brainstem response among infants with prenatal cocaine exposure

OBJECTIVE

To determine the auditory brainstem response (ABR) patterns in infants with prenatal cocaine exposure as detected by meconium analysis.

METHODS

Meconium drug analysis was done on term infants who were at risk for antenatal illicit drug exposure. Infants who tested positive for cocaine served as the exposed group; those who tested negative served as control subjects. An ABR was done on the infants within 6 days of life. Absolute latencies at 40 and 70 decibels (dB) of waves I, III, and V and interpeak latencies between I and III, III and V, and I and V were measured.

RESULTS

Among 58 infants in the study, 21 (35.6%) were positive, by meconium analysis, for cocaine and 5 (8.5%) were positive for cannabinoids. Four infants tested positive for cocaine, although their mothers denied illicit drug use. There was a significant difference in mean maternal age, gravidity, parity, birth weight, and head circumference among cocaine-exposed versus nonexposed infants. The ABR from cocaine-positive infants showed significantly prolonged mean absolute latencies in both ears as compared with nonexposed infants: right ear at 40 dB III (4.823 vs 4.447 milliseconds), 40 dB V (7.400 vs 6.968 milliseconds), 70 dB I (2.111 vs 1.631 milliseconds), and 70 dB III (4.122 vs 3.821 milliseconds); left ear at 40 dB III (4.820 vs 4.444 milliseconds), 40 dB V (7.460 vs 6.860 milliseconds), 70 dB I (2.063 vs 1.741 milliseconds), 70 dB III (4.026 vs 3.656 milliseconds), and 70 dB V (6.568 vs 6.258 milliseconds). The interpeak latency was not significantly different except in 1 cocaine-positive infant: left ear at 40 dB III to V (2.667 vs 2.417 milliseconds).

CONCLUSION

The ABR in neonates who are exposed prenatally to cocaine shows prolonged absolute peak latencies compared with nonexposed neonates and may indicate compromise of the auditory system from gestational exposure to cocaine that will need additional audiologic follow-up. Meconium analysis can more accurately detect the infants who are at risk.

Neurological soft signs and disruptive behavior among children of opiate dependent parents

The present study investigates the relationship between neurological soft signs and psychiatric symptoms among children of opiate dependent parents. A consecutive series of 102 children of opiate dependent parents received standardized psychiatric and neurological assessments. Symptoms of externalizing but not internalizing disorders associated with poor performance on the soft sign exam, controlling for age, intelligence, and socioeconomic status. Given the importance of externalizing disorders in the development of substance use disorders, studies of children at high risk for substance use disorder should also consider screening and assessment of children for soft neurological signs.

Fetal Alcohol and Drug Effects

BACKGROUND

Alcohol and drug use by pregnant women are harmful to the developing embryo and fetus. Teasing apart the specific contributions of each substance to adverse child outcome, however, proves difficult in practice. The risks to the neonate include intra-uterine growth retardation, birth defects, altered neurobehavior, and withdrawal symptoms. Subsequent behavior, development, and neurologic function may also be impaired.

REVIEW SUMMARY

Maternal cigarette smoking carries the greatest risk of impaired fetal growth of any of the substances discussed herein and has been linked to subsequent externalizing behaviors. Alcohol is a well-established teratogen. Heavy exposure to alcohol in a subset of infants is associated with fetal alcohol syndrome (FAS). Mental retardation is one of the main sequelae of alcohol exposure in utero. Fetal marijuana exposure has no consistent effect on outcome. Prenatal cocaine exposure has not been shown to have any detrimental effect on cognition, except as mediated through cocaine effects on head size. Although fetal cocaine exposure has been linked to numerous abnormalities in arousal, attention, and neurologic and neurophysiological function, most such effects appear to be self-limited and restricted to early infancy and childhood. Opiate exposure elicits a well-described withdrawal syndrome affecting central nervous, autonomic, and gastrointestinal systems, which is most severe among methadone-exposed infants.

CONCLUSION

Most adverse effects of prenatal drug exposure are self-limited, with catch-up growth and resolution of withdrawal and of prior neurobehavioral abnormalities noted over time. The exception is alcohol, which is linked to life-long impairments (i.e., mental retardation and microcephaly) and possibly cigarette-related behavioral effects. The absence of tangible evidence of detrimental long-term cocaine effects may reflect limitations in the methodology used to identify children at greatest risk for adverse outcome.

Comparison of meconium and neonatal hair analysis for detection of gestational exposure to drugs of abuse

BACKGROUND

Meconium and hair are two biological markers of in utero exposure to illicit drugs.

OBJECTIVE

To compare the sensitivity of the two tests for different drugs.

SETTING

Motherisk laboratory which tests in utero drug exposure in Toronto.

METHODS

Cocaine, benzoylecgonine, opiates, cannabis, benzodiazepines, methadone, and barbiturates were measured in pairs of hair and meconium samples from the same neonates.

RESULTS

Meconium was marginally more sensitive than neonatal hair for detection of cocaine and cannabis, possibly because it may detect second trimester exposure whereas hair grows only during the third trimester of pregnancy. There was a significant correlation between hair and meconium concentrations of cocaine, cannabis, and opiates.

CONCLUSION

In cases of clinical suspicion and a negative neonatal urine test, both meconium and hair are effective biological markers of in utero illicit drug exposure. Meconium may be more sensitive, but neonatal hair is available for three months whereas meconium is available for only one or two days. In contrast, the use of meconium, being a discarded material, is more acceptable to some parents than hair testing, which entails cutting scalp hair from the newborn.

Women in recovery discuss parenting while addicted to cocaine

PURPOSE

To identify what women recovering from cocaine addiction think is needed of them to be good parents.

DESIGN

An exploratory descriptive design using in-depth, semistructured interviews, conducted in the woman's home or in a treatment center. Demographics and pregnancy history were collected during the interview. A convenience sample of 11 mothers recovering from cocaine addiction participated.

RESULTS

Content analysis was used to analyze the interview data. Five themes emerged from the interviews: lack of structure, abandonment, impatience/anger, lack of parenting knowledge, and repeating dysfunctional patterns from family of origin.

CLINICAL IMPLICATIONS

Women addicted to cocaine who are parenting children need strong encouragement from the healthcare system to begin a recovery program and also to gain parenting skills. Discussions of child development and parenting stresses should be included during the recovery process from addiction because lack of parenting knowledge might be a major barrier for them. This study can help nurses to provide improved care for women who are parenting children while using cocaine or other drugs.

Neurologic complications of substance abuse

In addition to overdose, withdrawal, and addictive behavior, licit and illicit drugs produce a wide range of neurologic complications. Trauma results from intoxication and from violence related to a drug's illegality. Infection, including AIDS, is most often a consequence of parenteral use. Seizures can be secondary to either toxicity or withdrawal. Stroke can be ischemic or hemorrhagic. Persistent cognitive dysfunction affects alcoholics and probably users of other drugs as well. Teratogenicity is better documented for ethanol and tobacco than for illicit drugs. Other complications of recreational drug use include peripheral neuropathy, myelopathy, parkinsonism, leukoencephalopathy, optic atrophy, and cerebellar ataxia.

Central and autonomic system signs with in utero drug exposure

AIMS

To determine risk for central nervous system/autonomic nervous system (CNS/ANS) signs following in utero cocaine and opiate exposure.

METHODS

A multisite study was designed to determine outcomes of in utero cocaine and opiate exposure. A total of 11 811 maternal/infant dyads were enrolled. Drug exposed (EXP) infants were identified by maternal self report of cocaine or opiate use or by meconium testing. Of 1185 EXP, meconium analysis confirmed exposure in 717 to cocaine (CO) only, 100 to opiates (OP), and 92 to opiates plus cocaine (OP+CO); 276 had insufficient or no meconium to confirm maternal self report. Negative exposure history was confirmed in 7442 by meconium analysis and unconfirmed in 3184. Examiners masked to exposure status, assessed each enrolled infant. Using generalised estimating equations, adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated for manifesting a constellation of CNS/ANS outcomes and for each sign associated with cocaine and opiate exposure.

RESULTS

Prevalence of CNS/ANS signs was low in CO, and highest in OP+CO. Signs were significantly related to one another. After controlling for confounders, CO was associated with increased risk of manifesting a constellation of CNS/ANS outcomes, OR (95% CI): 1.7 (1.2 to 2.2), independent of OP effect, OR (95% CI): 2.8 (2.1 to 3.7). OP+CO had additive effects, OR (95% CI): 4.8 (2.9 to 7.9). Smoking also increased the risk for the constellation of CNS/ANS signs, OR (95% CI) of 1.3 (1.04 to 1.55) and 1.4 (1.2 to 1.6), respectively, for use of less than half a pack per day and half a pack per day or more.

CONCLUSION

Cocaine or opiate exposure increases the risk for manifesting a constellation of CNS/ANS outcomes.

Estimation of fetal exposure to drugs of abuse, environmental tobacco smoke, and ethanol

Many women worldwide use recreational drugs and alcohol. Details on the amounts and schedule of such exposures in pregnancy are often unreliable because of recall issues and shame and fears of legal action. Even when the report on maternal dose is correct, it does not necessarily reflect the amount reaching the fetus. Drugs of abuse accumulate in meconium and are incorporated into fetal hair on its growth. Recent work has documented the sensitivity and specificity of these assays for cocaine and other recreational drugs. Dose-response relationships between cocaine as measured in neonatal hair and head circumference or neurologic sequelae have been recently established. For ethanol, which cannot be measured in hair or meconium, accumulation of its fatty acid ethyl esters in meconium is emerging as a promising test for heavy maternal drinking in the second part of pregnancy. The identification of biologic markers of intrauterine exposure to xenobiotics will allow better understanding of etiology and dose-response relationships.

Neurological and developmental effects of HIV and AIDS in children and adolescents

HIV-related encephalopathy is an important problem in vertically infected children with HIV. Infected infants may manifest early, catastrophic encephalopathy, with loss of brain growth, motor abnormalities, and cognitive dysfunction. Even without evidence of AIDS, infected infants score lower than serorevertors on developmental measures, particularly language acquisition. Children with perinatal or later transfusion-related infection generally are roughly comparable developmentally to their peers until late in their course. Symptoms similar to adult AIDS dementia complex are occasionally seen in adolescents with advanced AIDS, including dementia, bradykinesia, and spasticity. Opportunistic CNS infections such as toxoplasmosis and progressive multifocal leukoencephalopathy are less common in children and adolescents than in adults. Increasing evidence suggests that aggressive antiretroviral treatment may halt or even reverse encephalopathy. Neuroimaging changes may precede or follow clinical manifestations, and include early lenticulostriate vessel echogenicity on cranial ultrasound, calcifying microangiopathy on CT scan, and/or white matter lesions and central atrophy on MRI. Differential diagnosis of neurological dysfunction in an HIV-infected infant includes the effects of maternal substance abuse, other CNS congenital infections, and other causes of early static encephalopathy. Initial entry of HIV into the nervous system occurs very early in infection. The risk of clinical HIV encephalopathy increases with very early age of infection and with high viral loads. Virus is found in microglia and brain derived macrophages, not neurons. The neuronal effect of HIV is probably indirect, with various cytokines implicated. Apoptosis is the presumed mechanism of damage to neurons by HIV.

Drugs of abuse in pregnancy

Care for the drug-using pregnant woman is being increasingly recognized as part of the obstetrician's role. There is great potential for improvement in provision of services for this group of women, partly because traditionally our antenatal clinics have not been perceived as being conducive to disclosure regarding drug use, but also because hard data and, indeed, randomized controlled trials on the subject, are scarce.From the little evidence available, and from our own experience in this area, we have attempted to outline the main problems encountered in the antenatal, intrapartum and postnatal periods with each of the main drugs of abuse and the management thereof. It is important to note that we include cigarette smoking and alcohol, probably the most commonly used drugs in pregnancy, and recognize that the picture is wider than the stereotypical emaciated intravenous heroin addict. Where possible, evidence from trial data is included, but much of the what is quoted is descriptive from personal experience from ourselves and others working in the field.

Influence of prenatal cocaine exposure on full-term infant neurobehavioral functioning

This study investigated infant neurobehavioral functioning during the newborn period in 334 full-term, African American neonates (187 cocaine exposed, 147 non-cocaine exposed) enrolled prospectively at birth, with documentation of drug exposure status through maternal interview and urine and meconium toxicology assays. Infants were assessed using the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) during the newborn period (0-6 postnatal days). Findings from multivariate profile analyses support a consistent, modest effect of prenatal cocaine exposure on neurobehavioral functioning in full-term neonates. All of the BNBAS cluster scores, with the exception of abnormal reflexes, were similarly affected, sharing a common slope (D=-0.14; 95% CI=-0.27, -0.003; P=.046) representing a -0.14 point difference between cocaine-exposed and non-cocaine-exposed infants after controlling for prenatal exposure to alcohol, tobacco, and marijuana (ATM); maternal age, education, employment, primigravida status, and prenatal care visits; and infant sex and postnatal age in days. Fetal growth was also related to neurobehavioral functioning and, in part, mediated the relationship between cocaine exposure and the BNBAS cluster scores. Cocaine exposure during each trimester similarly influenced infant neurobehavioral profiles, with cocaine-associated deficits most pronounced in infants with exposure in all three trimesters. Results from qualitative and quantitative urine and meconium bioassay indicators further substantiated these results. Findings, while significant, represent modest effect sizes in full-term infants.

The role of the placenta in variability of fetal exposure to cocaine and cannabinoids: A twin study

There is wide variability in the reported adverse fetal effects of cocaine and cannabinoids. The causes of this variability are largely unknown. We hypothesized that variability in placental handling of drugs affect fetal exposure. We used twin pregnancies as a paradigm to address the role of the placenta in this variability. We analyzed hair or meconium samples taken from dizygotic and monozygotic twins exposed in utero to illicit drugs. Out of 12 pairs, 5 had negative levels in both twins, and seven pairs of twins had chemical evidence of fetal exposure to cocaine (n = 5) or cannabinoids (n = 2). The one known monozygotic pair of twins had almost identical levels of cocaine. In contrast, the six dizygotic pairs had large disparities in either cocaine or cannabinoid concentrations. In three of these six dizygotic pairs, levels of cocaine (n = 2) or canabinoids (n = 1) were undetectable in one twin while positive in the other. Given that twins are theoretically exposed to similar maternal drug levels, our findings suggest that the placenta may have a major role in modulating the amounts of drug reaching the fetus.Key words: cocaine, cannabinoids, placenta, twins.