Prenatal exposure to amphetamines. Risks and adverse outcomes in pregnancy

Behavioral and social correlates of methamphetamine use in a population-based sample of early and later adolescents

This paper reports relationships between methamphetamine use and behaviors and social influences using data from a population-based survey of 8th- and 11th-grade students in Oregon for the 2001-2003 school years. We analyze methamphetamine use within a general problem behavior framework to identify malleable correlates of behavior for future prevention interventions. We specifically test two models of methamphetamine use employing logistic regression analysis: one comprised of behaviors and traits of the individual students and another focusing on peer and parental influences. This study finds adolescent methamphetamine use related to several problem behaviors. However, the specific problems vary by grade and are moderated by gender. Findings indicate the need for tailored interventions targeting gender/grade-specific behaviors or problems such as antisocial activities, risky sex, and depression, as well as social influences such as peers engaging in antisocial behaviors or using drugs and parents favoring drug use or poorly monitoring or setting limits for their children.

Neonatal amphetamine exposure and hippocampus-mediated behaviors

Previous studies linking amphetamine use during pregnancy to changes in the behavioral development of affected infants have greatly increased society's level of concern regarding amphetamine use by women of reproductive age. The aim of this study was to investigate whether exposure to d-amphetamine sulfate during the brain growth spurt, the most dynamic period of brain development, alters hippocampus-mediated behaviors during both pre-adolescence and young adulthood. Sprague-Dawley rat pups were intragastrically administered a milk formula containing 0, 5, 15 or 25 mg/kg/day of amphetamine from postnatal day (PD) 4-9. Following weaning, the effects of neonatal amphetamine exposure on hippocampus-mediated behaviors were assessed using the open-field, the water maze, and the conditioned taste aversion behavioral tasks. Results from these behavioral tests revealed that while amphetamine exposure during the brain growth spurt alters behaviors in open-field testing, it does not interfere with performance in either the water maze or the conditioned taste aversion paradigm. These results offer speculation that the effects of neonatal amphetamine exposure on hippocampus-mediated behaviors may be related to interactions between the "temporal" (time of drug exposure) and "regional" (different regions of the hippocampus) vulnerability issues.

Using umbilical cord tissue to detect fetal exposure to illicit drugs: a multicentered study in Utah and New Jersey

OBJECTIVE

We assessed umbilical cord tissue as a means of detecting fetal exposure to five classes of drugs of abuse.

STUDY DESIGN

In a multicentered study in Utah and New Jersey, we collected umbilical cord tissue when high-risk criteria were met for maternal illicit drug use. The deidentified umbilical cord specimens were analyzed for five drug classes: methamphetamine, opiates, cocaine, cannabinoids and phencyclidine. For each umbilical cord specimen, an enzyme-linked immunosorbent assay (ELISA)-based screening test was compared with a 'gold standard' test, consisting of gas or liquid chromatography tandem mass spectrometry.

RESULT

A total of 498 umbilical cord samples were analyzed of which 157 (32%) were positive using mass spectrometric detection. The sensitivity and specificity of the ELISA-based test for each class of drugs tested were as follows: methamphetamine 97 and 97%, opiates 90 and 98%, cocaine 90 and 100%, cannabinoids 96 and 98% and phencyclidine (only 1 of the 498 umbilical cord sample was positive for phencyclidine) 100 and 100%.

CONCLUSION

We judge that the performances of the ELISA-based tests are sufficient for clinical testing of fetal exposure to methamphetamine, opiates, cocaine and cannabinoids. Studies obtained on umbilical cord tissue can result in a more rapid return to the clinician than meconium testing, because waiting for meconium to be passed sometimes requires many days. Moreover, in some cases the meconium is passed in utero making collection impossible, whereas umbilical cord tissue should always be available for drug testing.

Oxoguanine glycosylase 1 protects against methamphetamine-enhanced fetal brain oxidative DNA damage and neurodevelopmental deficits

In utero methamphetamine (METH) exposure enhances the oxidative DNA lesion 7,8-dihydro-8-oxoguanine (8-oxoG) in CD-1 fetal mouse brain, and causes long-term postnatal motor coordination deficits. Herein we used oxoguanine glycosylase 1 (ogg1) knock-out mice to determine the pathogenic roles of 8-oxoG and OGG1, which repairs 8-oxoG, in METH-initiated neurodevelopmental anomalies. Administration of METH (20 or 40 mg/kg) on gestational day 17 to pregnant +/- OGG1-deficient females caused a drug dose- and gene dose-dependent increase in 8-oxoG levels in OGG1-deficient fetal brains (p < 0.05). Female ogg1 knock-out offspring exposed in utero to high-dose METH exhibited gene dose-dependent enhanced motor coordination deficits for at least 12 weeks postnatally (p < 0.05). Contrary to METH-treated adult mice, METH-exposed CD-1 fetal brains did not exhibit altered apoptosis or DNA synthesis, and OGG1-deficient offspring exposed in utero to METH did not exhibit postnatal dopaminergic nerve terminal degeneration, suggesting different mechanisms. Enhanced 8-oxoG repair activity in fetal relative to adult organs suggests an important developmental protective role of OGG1 against in utero genotoxic stress. These observations provide the most direct evidence to date that 8-oxoG constitutes an embryopathic molecular lesion, and that functional fetal DNA repair protects against METH teratogenicity.

Correlation of axon size and myelin occupancy in rats prenatally exposed to methamphetamine

The abuse of methamphetamine (MA) and other psychostimulants is a social and medical problem. In particular, the use of these drugs by pregnant women results in an increased number of children exposed prenatally to psychostimulants. Our previous work has demonstrated that prenatal exposure to MA affects the normal development of the rat visual system due to alterations of biochemical mechanisms and oxidative stress. It was also demonstrated that prenatal exposure to MA affects the dopaminergic system of the rat retina and optic nerve (ON) myelination. The present work was conducted to evaluate the effects of prenatal exposure to MA on the development of the ON in terms of axon growth and the myelin sheath. Pregnant female rats were given 5 mg/kg/day MA, subcutaneously (s.c.), in 0.9% saline from gestational day (GD) 8 to 22. The pair-fed control group was injected s.c. with an isovolumetric dose of 0.9% saline. Qualitative analysis was performed using representative electron ultramicrographs. Quantitative analysis was performed at an electron microscopic level on ON cross sections; parameters measured included myelinated/unmyelinated ratio, outer axon mean area, inner axon mean area, myelin mean area, myelin occupancy and distribution of axons by size. The ON of prenatally MA-exposed rats presented a higher rate of deformed axons and slighter lamellar separation. At PND 21, the average outer axon area of MA-treated males was significantly reduced. The average inner axon area only showed a significant difference between MA and control males for axons with an area of less than 0.3 microm(2). The average myelin area of MA-treated males was significantly reduced, and in MA-treated females was only significantly reduced in axons with an area of less than 0.3 microm(2). The percentage of myelin occupancy was significantly affected in MA-treated males, and in MA-treated females in the group of axons with an area of more than 0.3 microm(2). At PND 14 no significant differences were found between MA and control groups. The spectrum of ON myelinated axon size of MA-treated animals was shifted to the left at PND 14 and PND 21 for both genders. These results are in agreement with previous animal studies of prenatal and perinatal exposure to drugs of abuse. Taken together, these data indicate that the ON is vulnerable to early exposure to MA which causes developmental changes and may interfere with the functioning of the visual system.

Biological treatments for amfetamine dependence : recent progress

Amfetamine abuse has grown into a worldwide epidemic. Methamfetamine, a derivative of amfetamine made from readily accessible chemicals, has plagued the US since the 1960s, with an alarming recent surge in the numbers of those meeting the criteria for amfetamine abuse and dependence. We review this problem using a computerised literature search (PubMed 1964-2007) to summarise knowledge from animal and human studies about treatments for amfetamine dependence, while exploring the potential of pharmacogenetics to help uncover new treatment targets. Several promising therapeutic targets have come from animal models of reward, drug-taking behaviour and withdrawal. Although preclinical and selected clinical results have been promising, clinical studies have yielded inconsistent results. To improve these outcomes, pharmacogenetic studies may be used to identify candidate alleles that predict therapeutic response. Exciting preclinical findings and a steady progression of clinical results offer hope for the development of a treatment for amfetamine dependence.

Prenatal methamphetamine use and neonatal neurobehavioral outcome

BACKGROUND

Methamphetamine (MA) use among pregnant women is an increasing problem in the United States. How prenatal MA exposure affects neonatal neurobehavior is unknown.

OBJECTIVE

To examine the neurobehavioral effects of prenatal MA exposure.

DESIGN

The Infant Development, Environment and Lifestyle (IDEAL) study screened 13,808 subjects and 1632 were eligible and consented. 166 (n=74 exposed) were enrolled in a longitudinal follow-up. Exposure was determined by meconium assay and self-report with alcohol, marijuana, and tobacco present in both groups. The NICU Network Neurobehavioral Scale (NNNS) was administered within the first 5 days of life. Analyses conducted on NNNS summary scores included exposure group effects, heavy MA use effects, association with frequency of use by trimester, and dose-response relationships with amphetamine metabolites.

RESULTS

After adjusting for covariates, exposure to MA was associated with increased physiological stress. Heavy MA use was related to lower arousal, more lethargy, and increased physiological stress. First trimester MA use was related to elevated stress abstinence. Third trimester use was related to poorer quality of movement. Higher level of amphetamine metabolites in meconium was associated with increased CNS stress.

CONCLUSIONS

Prenatal MA exposure was associated with neurobehavioral patterns of decreased arousal, increased stress, and poor quality of movement. The dose-response relationships may represent neurotoxic effects from MA.

Support for selection of a methamphetamine cleanup standard in Colorado

Methamphetamine production for illicit use occurs in makeshift labs and is associated with the release of numerous chemicals, including methamphetamine residues. These methamphetamine residues may pose a health risk to residents who reoccupy these structures after property seizures. Several states have established technology-based cleanup standards for methamphetamine, but none have examined the health-protectiveness of these standards. In response to Colorado House Bill 04-1182, exposure intakes correlated with three technology-based standards were calculated for various groups of individuals. Intakes were assessed for a 1-year-old infant, 6-year-old child, and a female of childbearing age. Exposure intakes were compared to toxicity reference values developed from developmental endpoints following methamphetamine exposure from the available literature. Uncertainty factors were applied to the lowest adverse effect levels observed in these studies to arrive at the toxicity reference values. These reference values were greater than the calculated intakes from each proposed technology standard, suggesting that all of the proposed standards would be protective of human health exposure. The cost and practicality of attaining each of the proposed standards was also factored into the decision making process. In their final regulation (6 CCR 1014-3), the CDPHE selected 0.5 microg/100 cm(2) as the final cleanup standard for methamphetamine residues.

Periventricular leukomalacia and prenatal methamphetamine exposure: a case report

Periventricular leukomalacia (PVL) is a complication of prematurity that carries a high risk of long-term neurologic morbidity. We report the first case, to our knowledge, of unexpected PVL associated with in utero methamphetamine exposure in a 30-week gestation premature infant with a benign hospital course, who subsequently developed cerebral palsy by 24 months of life.

Effects of postnatal exposure to methamphetamine on the development of the rat retina

Since the development of different cell types in the retina occurs at different rates, it is possible that exposure to an exogenous substance may produce effects during one time period, but not during another. This study aims to analyze the effects of methamphetamine (METH) in the growth pattern of an experimental model as well as neurochemical and immunohistochemical parameters of the dopaminergic system of the rat retina. The three development stages chosen in this study are key markers in rat eye development. Rats were given 15 mg/kg body weight per day of METH as subcutaneous injections in 0.9% saline (3 mL/kg weight/day) from the day after birth PND 1 to PND 6, PND 13, and PND 29. Each daily dose was split into two. The control group was injected subcutaneously with saline. Both the schedule and volume for injecting saline in the control group were the same as for the METH-treated group. There were no significant differences in the total number of offspring per litter among treatment groups. All offspring had similar body weight at birth. Analysis of body weight on PND 1, showed that animals treated with METH had similar body weights to control-treated animals and females had smaller weights than males. For growth evolution, only litters with a sex ratio of four males and four females were used. Animals treated with METH had smaller body weights than the control-treated animals for all ages studied (PND 7, 14, and 30). Within the control group at PND 30, a significant difference was found in the body weight of females, which was lower when compared with males. For the postnatal model, 7 deaths occurred for the METH-exposed group. No deaths occurred in the control group in a total of 16 saline-injected litters comprising 186 pups. Although the levels of dopamine (DA) was within normal values for the postnatally exposed METH group when compared with its respective control group at PND 7 and 30, at PND 14 this was not the case: in this experimental group, the level of DA was lower than in the control group for both females and males. Support for this result was not evident from the TH immunoreactivity studies, probably because the methodology lacks the sensitivity to distinguish any mild effects, such as that observed in the postnatal model at PND 14. The level of the DA metabolite 3, 4-dihydroxyphenylacetic acid (DOPAC) remained unaffected at all ages studied, for both females and males. The results obtained in this study support the view that, during the critical periods in which the catecholamines can influence the development of neurones, METH transiently affects the pattern of the dopaminergic system in the developing retina.

Histological brain alterations following prenatal methamphetamine exposure in rats

When pregnant women abuse methamphetamine, the foremost concern is the potential adverse effect of this substance on fetal development. Clinical studies in humans have found that exposure to methamphetamine during brain development can cause neurobehavioral abnormalities, such as aggressive behavior, learning problems, and poor social adaptation. In the present study, we examined the effects of prenatal methamphetamine exposure on brain development in rats. The first group of pregnant rats was administered methamphetamine at a dose of 5 mg/kg/day during gestational day (GD 10 to GD 20 [MA]. The second group of pregnant rats was injected with saline vehicle only [SAL]. On GD 21 their fetuses were removed and fetal brains were observed. We found various types of morphological damage in MA fetal brains, including microgyria, ectopia, and hemorrhage. In some cases, abnormal distribution of the leptomeninx, such as breach or accumulation, was observed in addition to these histological abnormalities. Therefore, we examined the expression of laminin, which is an important component of the pia mater, in the fetal brains. However, Western blot analysis revealed that there was no difference in expression amount of laminin in whole fetal brain between the MA and SAL groups. We concluded that methamphetamine use during pregnancy can cause histological brain alterations in fetuses. Morphological alterations of brain seen in the present study and previous human studies following prenatal exposure to methamphetamine might be related to the neurobehavioral abnormalities seen in patients who had been exposed to methamphetamine in utero.

A developmental comparison of the neurobehavioral effects of ecstasy (MDMA)

The entactogen +/-3,4-methylenedioxymethamphetamine (MDMA or ecstasy) is a popular recreational drug among college, high school, and, occasionally, middle school students. Preclinical research examining the acute and long-term effects of MDMA has predominately been conducted in reproductively mature subjects but there has been increasing interest in adolescent and in utero exposure. This review examines the acute and long-term responses to MDMA during perinatal, adolescent, and adult periods. The ability of MDMA to alter core body temperature emerges gradually during ontogeny while a reduction in body weight is evident at all ages. Learning and working-memory are also altered independent of the developmental stage of exposure. Current evidence suggests adults are more sensitive to the long-term serotonin depletions following MDMA but younger ages also exhibit substantial and rapid neuroplasticity. Sexually dimorphic MDMA responses have been identified for the acute hyperthermic and motoric effects of MDMA with pubescent males being especially susceptible. Several physiological, behavioral, and neurochemical MDMA issues requiring further study are also outlined.

Comparison of monoamine and corticosterone levels 24 h following (+)methamphetamine, (+/-)3,4-methylenedioxymethamphetamine, cocaine, (+)fenfluramine or (+/-)methylphenidate administration in the neonatal rat

We have previously shown that neonatal administration of (+/-)3,4-methylenedioxymethamphetamine and (+)fenfluramine produce deficits in spatial and path integration learning, whereas (+)methamphetamine causes deficits in spatial learning. Conversely, cocaine and (+/-)methylphenidate have no effect on either form of learning following neonatal administration. The purpose of the present study was to determine whether corticosterone and/or monoamine levels were changed following subcutaneous administration of 10 mg/kg (+)methamphetamine, (+/-)3,4-methylenedioxymethamphetamine, (+)fenfluramine, (+/-)methylphenidate or cocaine every 2 h (total of four injections) on postnatal day 11. Twenty-four hours after the first dose, plasma, striatum and hippocampus were collected. Corticosterone levels were increased in methamphetamine-, fenfluramine-, methylenedioxymethamphetamine- and methylphenidate-treated rats relative to levels in saline-treated rats, whereas cocaine-treated rats were unaffected. In the striatum and hippocampus, serotonin and 5-hydroxyindolacetic acid were reduced in animals treated with methylenedioxymethamphetamine or fenfluramine, compared with levels in saline controls. Dopamine levels were not changed by any of the drugs, although 3,4-dihydroxyphenylacetic acid was decreased following methylenedioxymethamphetamine or methamphetamine. Minimal effects were seen in neurotransmitter levels following injection of cocaine or methylphenidate. These data suggest that drugs that affect corticosterone and hippocampal serotonin are associated with both spatial learning and path integration deficits, and those that affect corticosterone and 3,4-dihydroxyphenylacetic acid are associated with spatial learning deficits only.

The infant development, environment, and lifestyle study: effects of prenatal methamphetamine exposure, polydrug exposure, and poverty on intrauterine growth

OBJECTIVE

Methamphetamine use among pregnant women is an increasing problem in the United States. Effects of methamphetamine use during pregnancy on fetal growth have not been reported in large, prospective studies. We examined the neonatal growth effects of prenatal methamphetamine exposure in the multicenter, longitudinal Infant Development, Environment and Lifestyle study.

DESIGN/METHOD

The Infant Development, Environment and Lifestyle study screened 13808 subjects at 4 clinical centers: 1618 were eligible and consented, among which 84 were methamphetamine exposed, and 1534 were unexposed. Those who were methamphetamine exposed were identified by self-report and/or gas chromatography-mass spectrometry confirmation of amphetamine and metabolites in infant meconium. Those who were unexposed denied amphetamine use and had a negative meconium screen. Both groups included prenatal alcohol, tobacco, or marijuana use, but excluded use of opiates, LSD, PCP or cocaine only. Neonatal parameters included birth weight and gestational age in weeks. One-way analysis of variance and linear-regression analyses were conducted on birth weight by exposure. The relationship of methamphetamine exposure and the incidence of small for gestational age was analyzed using multivariate logistic-regression analyses.

RESULTS

The methamphetamine exposed group was 3.5 times more likely to be small for gestational age than the unexposed group. Mothers who used tobacco during pregnancy were nearly 2 times more likely to have small-for-gestational-age infants. In addition, less maternal weight gain during pregnancy was more likely to result in a small-for-gestational-age infant. Birthweight in the methamphetamine exposed group was lower than the unexposed group.

CONCLUSIONS

These findings suggest that prenatal methamphetamine use is associated with fetal growth restriction after adjusting for covariates. Continued follow-up will determine if these infants are at increased risk for growth abnormalities in the future.

Effects of Prenatal Exposure to Methamphetamine on the Development of the Rat Retina

In recent years there has been growing use of methamphetamine (METH) by pregnant women, resulting in an increasing number of children exposed prenatally to this drug of abuse. METH is known to be potentially neurotoxic to human adults, but there is minimal information with respect to the consequences of such exposure to the fetus. The purpose of this study was to ascertain external parameters of animal development, as well as neurochemical and immunohistochemical alterations at three key points of retinal development (postnatal day [PND] 7, 14, and 30). Rats of the Wistar strain were used in this experimental model. Pregnant females received a dose of 5 mg/kg body weight per day of METH-HCl in 0.9% saline, from gestational day (GD) 8 to 22. The control group to be used was pair fed and saline injected. Litters were randomly culled at PND 1 to 8 pups. Analysis of maternal body weight gain during pregnancy showed that females treated with METH had lower body weights than control-treated females. The body weight on PND 1, showed that animals treated with METH prenatally had smaller body weights than the control-treated animals and also that females weighed less than males. Prenatal exposure to METH did not alter the retinal levels of 3,4-dihydroxyphenylacetic acid (DOPAC) in the male group and the level of dopamine (DA) in both female and male groups when compared with their respective pair fed control groups during the first month of life. Correlating with the neurochemical data, no obvious changes on the localization of TH immunoreactivity in the rat retina at PND 7, 14, and 30 could be detected between control and METH-treated animals. Thus, exposure to METH disrupted this pattern in a gender-dependent manner. These data confirm previous observation that developing rats are protected against the adult type of METH-induced neurotoxicity. Therefore, conventional markers used for adult animals appear to be unsatisfactory to demarcate boundaries of the PND 1 to 30 critical periods.

Myelination changes in the rat optic nerve after prenatal exposure to methamphetamine

The use of psychostimulants during adolescence and early adult life has increased in recent years. It is known that these substances affect the sensory systems, and the optic nerve has been shown to be a target tissue. This work was conducted to evaluate the effects of prenatal exposure to methamphetamine (MA) on the developmental pattern of the rat optic nerve. Pregnant female rats were given 5 mg/kg body weight/day MA, s.c., in 0.9% saline from gestational days 8 to 22. The control group was injected with an isovolumetric dose of 0.9% saline. Animal model parameters, such as gestational body weight evolution, food intake and pups parameters were registered. The offspring were sacrificed at postnatal days (PND) 7, 14 and 21. Morphometric analyses were performed at light and electron microscopic levels on optic nerve cross sections; parameters measured included optic nerve diameter and area, axonal density, total number of axons and myelin thickness. Myelin basic protein (MBP) was measured by western blotting in optic nerve samples at PND14 and PND21. The animal model parameters, such as maternal and pup weight, showed no significant differences between MA and control groups. Optic nerve diameter was smaller at PND7 in the male MA group and in both male and female MA groups at PND21. The mean cross-sectional area was smaller at PND14 in the male MA group and in both male and female groups at PND21. The total number of myelinated axons did not vary between groups at any of the studied ages. The myelin thickness of the axons in MA-treated females was thinner when compared with the respective control group at PND21. No other differences were found concerning myelin thickness. There was a reduction of MBP protein expression in MA-injected females at PND14 and PND21. The combined results suggest that prenatal exposure to MA affects the myelination process.

Drugs of abuse testing in meconium

Prenatal substance abuse is an ongoing concern with significant impact on neonatal health and development across socioeconomic lines. Meconium, passed by neonates during their first post-natal bowel movements, is a matrix unique to the developing fetus and contains a long history of prenatal metabolism. Over the last two decades, the use of meconium as a matrix for assessing prenatal exposure to drugs of abuse has yielded methods exhibiting higher sensitivity, easier collection, and a larger window of detection than traditional matrices. Recently, a method has been developed for the analysis of fatty acid ethyl esters in meconium as a biomarker of fetal alcohol exposure, potentially facilitating the future diagnosis of Fetal Alcohol Spectrum Disorder in situations where gestational alcohol consumption history is unknown. Screening for prenatal exposure to illicit and abused licit drugs in meconium is possible by use of a variety of immunoassay methods with conformational analysis usually occurring by GCMS or LCMS. In spite of increased sample preparation time relative to blood and urine, the long metabolic history, coupled with the ease and wide window of collection of meconium make it the ideal matrix for determining fetal drug exposure.

Methamphetamine and other substance use during pregnancy: preliminary estimates from the Infant Development, Environment, and Lifestyle (IDEAL) study

OBJECTIVES

Methamphetamine use is a continuing problem in several regions of the United States and yet few studies have focused on prenatal methamphetamine exposure. The purpose of this study was to estimate the prevalence and correlates of alcohol, tobacco, and other substance use-including methamphetamine-during pregnancy.

METHODS

The sample consisted of the first 1632 eligible mothers who consented to participate in a large-scale multisite study focused on prenatal methamphetamine exposure. This unselected screening sample included both users and nonusers of alcohol, tobacco, methamphetamine, and other drugs. Substance use was determined by maternal self-report and/or GC/MS confirmation of a positive meconium screen.

RESULTS

Overall, 5.2% of women used methamphetamine at some point during their pregnancy. One quarter of the sample smoked tobacco, 22.8% drank alcohol, 6.0% used marijuana, and 1.3% used barbiturates prenatally. Less than 1% of the sample used heroin, benzodiazepines, and hallucinogens. Multivariate modeling results showed that tobacco smokers and illicit drug users were more likely to be single and less educated, have attended less than 11 prenatal visits, and utilize public financial assistance.

CONCLUSIONS

This is the first large-scale investigation to report the prevalence of methamphetamine use during pregnancy in areas of the United States where methamphetamine is a notable concern. Follow-up research is ongoing to investigate the outcomes associated with prenatal methamphetamine exposure. Given that this research extends and confirms previous findings showing that high-risk groups of pregnant women can be identified on the basis of basic demographic characteristics, targeted interventions are greatly needed to reduce serious adverse outcomes associated with prenatal alcohol and tobacco use.

Methamphetamine and lipid peroxidation in the rat retina

BACKGROUND

The use of psychoactive drugs during adolescence and early adult life has increased in the last few decades. It is known that developmental exposure to psychostimulants affects the sensory systems, and the retina has been shown to be a target tissue. This work was conducted to evaluate the pattern of lipid peroxidation in the rat retina following prenatal exposure to methamphetamine (MA).

METHODS

Pregnant female Wistar rats were given MA (5 mg/kg of body weight/day; SC, in 0.9% saline) from GD 8 to 22. Offspring were sacrificed at postnatal days (PNDs) 7, 14, and 21. The retinas were homogenized, and both the total antioxidant and superoxide dismutase (SOD) activities were measured by enzymatic-colorimetric methods. The lipid peroxidation byproducts (malondialdehyde [MDA] and MDA-like metabolites) were measured by the thiobarbituric acid test.

RESULTS

Total antioxidant levels were lower in the MA group at PND 21 in both males and females. The activity of SOD was higher in PND 7 females from the MA group. MDA levels were higher in the MA group at PND 21 in both genders.

CONCLUSIONS

These findings suggest that prenatal-induced MA toxicity in the retina may be related to lipid peroxidation processes and oxidative stress.

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.

Recreational drugs and fetal gastroschisis: maternal hair analysis in the peri-conceptional period and during pregnancy

OBJECTIVE

To objectively measure individual recreational drug groups in maternal hair samples timed for the period of conception and different stages of pregnancy in expectant mothers with a diagnosis of fetal gastroschisis.

DESIGN

Prospective observational study.

SETTING

Tertiary level Fetal Medicine Unit in a University teaching hospital.

POPULATION

Pregnant women with a diagnosis of fetal gastroschisis (n= 22) and a control group of women (n= 25) with a normal fetus.

METHODS

Hair samples were cut from the vertex of the head of expectant mothers with a diagnosis of fetal gastroschisis and a matched control group in whom the fetus was normal. The samples were analysed by enzyme-linked immunosorbent assay (ELISA) for individual drug groups. Confirmatory tests using gas chromatography with mass spectrometry (GCMS) were used.

MAIN OUTCOME MEASURES

Presence of recreational drug compounds in hair samples.

RESULTS

In the group with fetal gastroschisis there were four proven positive cases for recreational drug abuse (18%) and there were none in the control group.

CONCLUSIONS

The incidence of recreational drug use in the peri-conceptional period and the first trimester by expectant mothers with a diagnosis of fetal gastroschisis is 18%. This association may be linked to the recent increase in the incidence of gastroschisis among younger mothers.

Methamphetamine-enhanced embryonic oxidative DNA damage and neurodevelopmental deficits

Methamphetamine (METH) causes dopaminergic nerve terminal degeneration and functional deficits in adult mice, but its neurodevelopmental effects are unclear. We investigated METH-initiated oxidative DNA damage in brain during the embryonic and fetal periods, and the postnatal histological and functional consequences. Pregnant CD-1 mice were treated with a single dose of METH (20 or 40 mg/kg ip) or its saline vehicle on Gestational Day 14 or 17. METH enhanced conceptal DNA oxidation, determined by 8-oxoguanine formation, in brain and liver by at least 2-fold at 1 h (P < 0.05), and more so in some fetal brains at 4 h. After birth, motor coordination on the rotarod apparatus in the METH-exposed offspring was impaired for at least 12 weeks (P < 0.05). Unlike in adults, this postnatal functional deficit in offspring exposed in utero to METH was not associated with degeneration of striatal dopaminergic nerve terminals at 12 weeks of age determined by tyrosine hydroxylase staining, suggesting a novel pathological mechanism in utero. This is the first evidence of oxidative DNA damage in embryonic and fetal brain caused by amphetamines, leading to long-term postnatal neurodevelopmental deficits via a mechanism different from that underlying the neurodegeneration observed in METH-exposed adults.

Substance use during pregnancy: risk factors and obstetric and perinatal outcomes in South Australia

OBJECTIVE

To determine the prevalence of self-reported substance use during pregnancy in South Australia, the characteristics of substance users, their obstetric outcomes and the perinatal outcomes of their babies.

METHODS

Multivariable logistic regression with STATA statistical software was undertaken using the South Australian perinatal data collection 1998-2002. An audit was conducted on every fifth case coded as substance use to identify the actual substances used.

RESULTS

Substance use was reported by women in 707 of 89 080 confinements (0.8%). Marijuana (38.9%), methadone (29.9%), amphetamines (14.6%) and heroin (12.5%) were most commonly reported, with polydrug use among 18.8% of the women audited. Substance users were more likely than non-users to be smokers, to have a psychiatric condition, to be single, indigenous, of lower socio-economic status and living in the metropolitan area. The outcome models had poor predictive powers. Substance use was associated with increased risks for placental abruption (OR 2.53) and antepartum haemorrhage from other causes (OR 1.41). The exposed babies had increased risks for preterm birth (OR 2.63), small for gestational age (OR 1.79), congenital abnormalities (1.52), nursery stays longer than 7 days (OR 4.07), stillbirth (OR 2.54) and neonatal death (OR 2.92).

CONCLUSIONS

Substance use in pregnancy is associated with increased risks for antepartum haemorrhage and poor perinatal outcomes. However, only a small amount of the variance in outcomes can be explained by the substance use alone. Recent initiatives to improve identification and support of women exposed to adverse health, psychosocial and lifestyle factors will need evaluation.

Identification and Management of Neonatal Abstinence Syndrome

The nursing care of infants experiencing withdrawal from drug abuse through passive exposure is often challenging. These infants are at higher risk for many medical complications in addition to withdrawal itself. Often, infusion nurses play an important role in caring for an infant with drug withdrawal by providing infusion therapy for the infant's compromised medical condition, poor oral intake, and withdrawal symptoms. This article focuses on drug abuse during pregnancy, the withdrawal symptoms it may cause in the infant, ways to recognize an infant experiencing neonatal abstinence syndrome, and available scoring tools and treatment options.

Implications of chronic methamphetamine use: a literature review

Methamphetamine (MA) abuse is increasing to epidemic proportions, both nationally and globally. Chronic MA use has been linked to significant impairments in different arenas of neuropsychological function. To better understand this issue, a computerized literature search (PubMed, 1964-2004) was used to collect research studies examining the neurobiological and neuropsychiatric consequences of chronic MA use. Availability of MA has markedly increased in the United States due to recent technological improvements in both mass production and clandestine synthesis, leading to significant public health, legal, and environmental problems. MA intoxication has been associated with significant psychiatric and medical comorbidity. Research in animal models and human subjects reveals complicated mechanisms of neurotoxicity by which chronic MA use affects catecholamine neurotransmission. This pathology may underlie the characteristic cognitive deficits that plague chronic MA users, who experience impairments in memory and learning, psychomotor speed, and information processing. These impairments have the potential to compromise, in turn, the ability of MA abusers to engage in, and benefit from, psychosocially based chemical-dependency treatment. Development of pharmacological interventions to improve these cognitive impairments in this population may significantly improve the degree to which they may be able to participate in treatment. Atypical antipsychotics may have some promise in this regard.

The effect of controlled drugs on the unborn child and fetus

Illicit substance abuse is more prevalent than thought in women of a child bearing age and its incidence is increasing. Although maternal factors, such as poor socioeconomic status, diet, smoking, alcohol and infection, have detrimental effects on the fetuses of drug-abusing mothers, harm is increased due to the pharmacological activity of the drugs themselves. This article reviews the pharmacophysiological interactions between mother and fetus, describes the general effects of substance abuse during each trimester and details the deleterious effects on the fetus of the more commonly abused controlled drugs.

Smaller subcortical volumes and cognitive deficits in children with prenatal methamphetamine exposure

The purpose of this pilot study was to examine possible neurotoxic effects of prenatal methamphetamine (Meth) exposure on the developing brain and on cognition. Meth-exposed children (n=13) and unexposed control subjects (n=15) were evaluated with MRI. Global brain volumes and regional brain structures were quantified. Ten Meth-exposed and nine unexposed children also completed neurocognitive assessments. Meth-exposed children scored lower on measures of visual motor integration, attention, verbal memory and long-term spatial memory. There were no differences among the groups in motor skills, short delay spatial memory or measures of non-verbal intelligence. Despite comparable whole brain volumes in each group, the Meth-exposed children had smaller putamen bilaterally (-17.7%), smaller globus pallidus (left: -27%, right: 30%), smaller hippocampus volumes (left: -19%, right: -20%) and a trend for a smaller caudate bilaterally (-13%). The reduction in these brain structures correlated with poorer performance on sustained attention and delayed verbal memory. No group differences in volumes were noted in the thalamus, midbrain or the cerebellum. In summary, compared with the control group, children exposed to Meth prenatally exhibit smaller subcortical volumes and associated neurocognitive deficits. These preliminary findings suggest prenatal Meth exposure may be neurotoxic to the developing brain.

Maternal methamphetamine administration during pregnancy influences on fetal rat heart development

Methamphetamine (MAP) is one of the most abused drugs in Japan. The rate of MAP abuse by young women has recently reached more than 50 percent in adolescents. A major health concern is that these women will continue to use MAP during pregnancy. The purpose of this study was to investigate whether MAP administered to the mother during pregnancy would change the expression of alpha- and beta- myosin heavy chain (MHC) mRNA in rat neonatal hearts, as detected by quantitative RT-PCR. In addition, morphological changes in the rat neonatal ventricles were examined. Pregnant rats were injected intraperitoneally with MAP (1 mg/kg/day) starting at day 0 of gestation and ending at day 21. There was a significant increase in alpha-MHC mRNA expression in the neonatal ventricular muscle in the experimental group compared with the control at postnatal day (P) 0 and 5. alpha-MHC mRNA expression in both groups was similar after P9. beta-MHC mRNA expression was similar in both groups at P0. Postnatal beta-MHC mRNA expression decreased rapidly, but significant alteration was not detected. Neonatal rats at P0 exhibited some cardiac changes, including hypertrophy, degeneration, and disarrangement of myofibers, but these lesions disappeared by P14. We conclude that chronic maternal administration of MAP changes the alpha- and beta-MHC mRNA expression pattern in fetal and neonatal hearts, correlating with abnormal development, plasma level of hormones, and myocardial damage. At the same time, it is indicated that neonatal cardiomyocytes have reversibility.

Methamphetamine-induced gene expression profiles in the striatum of male rat pups exposed to the drug in utero

Methamphetamine is a neurotoxic pychostimulant which affects monoaminergic and non-monoaminergic systems in the brain. Clinical studies in humans have found that exposure to methamphetamine in the developing embryo can cause significant behavioral and cognitive anomalies later in life. Exposure of animals to methamphetamine (METH) in utero can cause neurobehavioral effects that do not become apparent until young adulthood. In the present study, we sought to determine the effects of in utero METH exposure on the striata of perinatal rat pups using a recently developed 17 k cDNA microarray. We found that METH administration caused alterations in 913 genes according to strict criteria. These alterations include changes in genes that participate in signal transduction, heat shock responses and neuronal development. The majority of the changes in gene expression were more prominent at the 7-day time point. These observations suggest that in utero METH exposure might initiate molecular programs that significantly impact gene expression during the developmental period long after the last exposure to this drug. Thus, during development, METH exposure in utero might cause significant long-term changes in gene expression that might constitute, in part, some of the substrates for the behavioral and cognitive anomalies reported in the literature.

Labor analgesia for the drug abusing parturient: is there cause for concern?

Drug abuse has crossed geographic, economic and social borders, and it remains one of the major problems facing our society today. The prevalence of recreational drug abuse among young adults (including women) has increased markedly over the past two decades. Nearly 90% of drug abusing women are of childbearing age. Consequently, it is not surprising to find pregnant women with a history of drug addiction. Obstetricians and obstetric anesthesiologists become involved in the care of drug abusing patients either in emergency situations, such as placental abruption, uterine rupture or fetal distress, or in more controlled situations, such as request for labor analgesia. The diverse clinical manifestations of maternal substance abuse may result in life-threatening complications and significantly impact the peripartum care of these patients.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to list the most commonly abused substances during pregnancy, to describe the various effects of particular substances on pregnancy including the mechanism of desired effect for various substances, and to outline the obstetric anesthesia recommendations for the various substances abused during pregnancy.

The pre-clinical behavioural pharmacology of 3,4-methylenedioxymethamphetamine (MDMA)

3,4-Methylenedioxymethamphetamine (MDMA) is a relatively novel drug of abuse and as such little is currently known of its behavioural pharmacology. This review aims to examine whether MDMA represents a novel class of abused drug. MDMA is known as a selective serotonergic neurotoxin in a variety of animal species but acutely it is a potent releaser and/or reuptake inhibitor of presynaptic serotonin, dopamine, noradrenaline, and acetylcholine. Interaction of these effects contributes to its behavioural pharmacology, in particular its effects on body temperature. Drug discrimination studies indicate that MDMA and related drugs produce unique interoceptive effects which have led to their classification as entactogens. This is supported by results from other behavioural paradigms although there is evidence for dose dependency of MDMA-specific effects. MDMA also produces conditioned place preference but is not a potent reinforcer in self-administration studies. These unique behavioural effects probably underlie its current popularity. MDMA is found in the street drug ecstasy but it may not be appropriate to equate the two as other drugs are routinely found in ecstasy tablets

Effects of prenatal methamphetamine exposure on fetal growth and drug withdrawal symptoms in infants born at term

To determine fetal growth and the incidence of withdrawal symptoms in term infants exposed to methamphetamine in utero, we retrospectively identified neonates whose mothers used methamphetamine during pregnancy and matched them to unexposed newborns. Exclusion criteria included multiple and preterm gestations. Although there were no differences in infant growth parameters between the methamphetamine-exposed and methamphetamine-unexposed neonates, methamphetamine exposure throughout gestation was associated with decreased growth relative to infants exposed only for the first two trimesters. In addition, there were significantly more small for gestational age infants in the methamphetamine group compared with the unexposed group. Methamphetamine-exposed infants whose mothers smoked had significantly decreased growth relative to infants exposed to methamphetamine alone. Withdrawal symptoms (as determined by a previously reported scoring system) requiring pharmacologic intervention were observed in 4% of methamphetamine-exposed infants. These preliminary findings indicate that methamphetamine use is associated with growth restriction in infants born at term.

Neonatal perturbation of neurotrophic signaling results in abnormal sensorimotor gating and social interaction in adults: implication for epidermal growth factor in cognitive development

Epidermal growth factor (EGF) and its structurally related proteins are implicated in the developmental regulation of various brain neurons, including midbrain dopaminergic neurons. There are EGF and EGF receptor abnormalities in both brain tissues and blood from schizophrenic patients. We administered EGF to neonatal rats to transiently perturb endogenous EGF receptor signaling and evaluated the neurobehavioral consequences. EGF-treatment-induced transient impairment in tyrosine hydroxylase expression. The animals grew normally, exhibited normal weight increase, glial growth, and gross brain structures, and later lost the tyrosine hydroxylase abnormality. During and after development, however, the rats began to display various behavioral abnormalities. Abnormal sensorimotor gating was apparent, as measured by deficits in prepulse inhibition of acoustic startle. Motor activity and social interaction scores of the EGF-treated animals were also impaired in adult rats, though not in earlier developmental stages. In parallel, there was a significant abnormality in dopamine metabolism in the brain stem of the adult animals. Gross learning ability appeared to be normal as measured by active avoidance. These behavioral alterations, which are often present in schizophrenic models, were ameliorated by subchronic treatment with clozapine. Although the molecular and/or physiologic background(s) of these behavioral abnormalities await further investigation, the results of the present experiment indicate that abnormal EGF receptor stimulation given during limited neonatal stages can result in severe and persistent cognitive/behavioral dysfunctions, which appear only in adulthood.

Fetal exposure to methamphetamine in utero stimulates development of serotonergic neurons in three-dimensional reaggregate tissue culture

Methamphetamine is a potent psychomotor stimulant with neurotoxic potential which is widely abused by females of childbearing age, raising serious public health concerns in terms of exposure of the fetus to the drug. The current study was conducted to determine the effect of maternal administration of methamphetamine on developing monoaminergic neurons using three-dimensional reaggregate tissue cultures prepared from fetal mesencephalic and striatal cells. In this culture system, the dopaminergic and serotonergic mesencephalic-striatal projections are reconstructed and develop with a time course similar to that observed in vivo. Pregnant C57Bl/6J mice were injected twice daily with 40 mg/kg methamphetamine or saline from gestational days 6-13. On gestational day 14, cells from methamphetamine and saline-exposed embryos were used to prepare reaggregate cultures. Levels of neurotransmitters and their metabolites in the reaggregates and culture medium were monitored at 14, 29, 43, and 64 days of culture. Reaggregates prepared from methamphetamine-exposed embryos showed a significant elevation in serotonin levels at all culture ages compared to reaggregates prepared from saline-treated embryos. Levels of 5-HIAA in reaggregates and culture medium were also elevated in 14- and 29-day-old cultures derived from drug-exposed embryos. The development of the dopaminergic nigrostriatal projection was resistant to repeated in utero exposure to methamphetamine. In contrast, exposure of the fetus to methamphetamine, during early to midgestation, produced a long-lasting stimulatory effect on serotonergic development in culture.

Effects of acute and repeated methamphetamine treatment on the ultrasonic vocalizations of postnatal rats

Repeated exposure to cocaine (COC) has been reported to both increase ultrasonic vocalizations (USVs) of postnatal rats and enhance the crying of human infants. The purpose of the present study was to determine whether acute or repeated treatment with another commonly abused psychostimulant, methamphetamine (MAP), would affect the USV production of postnatal rats. In the first experiment, USVs were measured 30 min after rats were given an acute injection of saline or MAP (1, 2, 4, or 8 mg/kg ip) on postnatal day (PD) 10. In the second experiment, rats were exposed to MAP (0, 1, or 4 mg/kg/day ip) on PD 2-8 or PD 2-9. On PD 10, rats were given an acute injection of saline or MAP (1 or 4 mg/kg ip) 30 min prior to behavioral assessment. Results showed that acute treatment with MAP (4 or 8 mg/kg) decreased the USVs of rats on PD 10, while repeated exposure to MAP did not affect the USV emissions of rats subsequently treated with saline or MAP. The reason why acute MAP treatment decreased USV production is uncertain, but it is possible that MAP alleviates isolation distress by stimulating reward processes. Alternatively, MAP increases heart rate and blood pressure, so acute treatment with this drug may decrease USV emissions through peripheral physiological mechanisms (i.e., by reducing abdominal compression reactions).

Methamphetamine concentrations in fetal and maternal brain following prenatal exposure

Levels of methamphetamine in maternal striatum and whole fetal mouse brain were assessed at 0.5, 1, 2, and 4 h postinjection on gestational day 14 (GD14) following a single, subcutaneous injection of 40 mg/kg (+)-methamphetamine hydrochloride to pregnant mice. In the dams, striatal concentrations of methamphetamine peaked at 1 h postinjection, reaching levels of approximately 510 ng/mg protein. Amphetamine, the primary metabolite of methamphetamine, increased to 77 ng/mg protein at 2 h and remained elevated by 4 h postinjection. In the fetal brain, peak methamphetamine concentrations of approximately 122 ng/mg protein were attained at 1 h. Amphetamine was only detectable in fetal brain at 2 and 4 h postinjection. Regional analysis of methamphetamine levels in fetal striatum, cortex, and brainstem revealed that the drug was not uniformly distributed. Maternal administration of methamphetamine results in fetal brain drug concentrations, which approximate those reported in human infants whose mother abused methamphetamine. This dosage regimen, therefore, serves as an appropriate animal model for assessing the potential risks to human offspring exposed to methamphetamine in utero.

Prenatal drug exposure and social policy: the search for an appropriate response

Prenatal drug exposure continues to be a controversial topic. Views of what constitutes an appropriate response to drug-exposed infants vary, in large part due to the many complex issues endemic to perinatal substance use. The purpose of this article is to review the controversy surrounding prenatal drug exposure, outline the policy dilemmas that complicate attempts to respond appropriately, review current practice in this area and the effectiveness of those practices, and offer specific recommendations as a starting point for debate. It is suggested that earlier controversy regarding the sequelae of prenatal drug exposure may be decreasing as research identifies specific and subtle deficits in some affected infants. It is also suggested that the postnatal effects of parental substance abuse (e.g., in terms of abuse/neglect, attachment, and development) are the more appropriate focus of child protection efforts, and that different disciplines must collaborate to reach a consensus regarding the nature of these efforts.