Identification of prenatal amphetamines exposure by maternal interview and meconium toxicology in the Infant Development, Environment and Lifestyle (IDEAL) study

Biological Testing and Interpretation of Laboratory Results Associated with Detecting Newborns with Substance Exposure

BACKGROUND

Substance use during pregnancy is common, as is biological testing that is intended to help identify prenatal exposures. However, there is no standardized requirement for biological testing with either maternal or newborn specimens, nor is there standardization related to when testing occurs, how frequently testing occurs, what specimen(s) to test, what substances to test for, or how to perform testing.

CONTENT

We review common specimen types tested to detect maternal and newborn substance exposure with a focus on urine, meconium, and umbilical cord tissue. We also review common analytical methods used to perform testing, including immunoassay, and mass spectrometry platforms. Considerations regarding the utilization of testing relative to the purpose of testing, the drug analyte(s) of interest, the specific testing employed, and the interpretation of results are emphasized to help guide decisions about clinical utilization of testing. We also highlight specific examples of unexpected results that can be used to guide interpretation and appropriate next steps.

SUMMARY

There are strengths and limitations associated with all approaches to detecting substance exposure in pregnant persons as well as biological testing to evaluate a newborn with possible substance exposure. Standardization is needed to better inform decisions surrounding evaluation of substance exposures in pregnant people and newborns. If biological sampling is pursued, testing options and results must be reviewed in clinical context, acknowledging that false-positive and -negative results can and do occur.

The impact of pregnancy and associated hormones on the pharmacokinetics of Δ9-tetrahydrocannabinol

INTRODUCTION

(-)-Δ9-tetrahydrocannabinol (THC) is the main psychoactive component of cannabis. Cannabis is the most widely used drug of abuse by pregnant individuals, but its maternal-fetal safety is still unclear. The changes in THC disposition during pregnancy may affect THC safety and pharmacology.

AREAS COVERED

This review summarizes the current literature on THC metabolism and pharmacokinetics in humans. It provides an analysis of how hormonal changes during pregnancy may alter the expression of cannabinoid metabolizing enzymes and THC and its metabolite pharmacokinetics. THC is predominately (>70%) cleared by hepatic metabolism to its psychoactive active metabolite, 11-OH-THC by cytochrome P450 (CYP) 2C9 and to other metabolites (<30%) by CYP3A4. Other physiological processes that change during pregnancy and may alter cannabinoid disposition are also reviewed.

EXPERT OPINION

THC and its metabolites disposition likely change during pregnancy. Hepatic CYP2C9 and CYP3A4 are induced in pregnant individuals and in vitro by pregnancy hormones. This induction of CYP2C9 and CYP3A4 is predicted to lead to altered THC and 11-OH-THC disposition and pharmacodynamic effects. More in vitro studies of THC metabolism and induction of the enzymes metabolizing cannabinoids are necessary to improve the prediction of THC pharmacokinetics in pregnant individuals.

Drug testing in support of the diagnosis of neonatal abstinence syndrome: The current situation

Illicit drug use during pregnancy is a concern worldwide, with many international studies describing attempted strategies to mitigate this problem. Drug misuse during pregnancy is associated with significant maternal as well as perinatal complications, which include a high incidence of stillbirths, fetal distress, neonatal abstinence syndrome (NAS) and increased neonatal mortality. Unfortunately, the identification of a drug-exposed mother or neonate is challenging. Maternal disclosure of drug use is often inaccurate, principally due to psychosocial factors including behavioral denial or the fear of the consequences resulting from such admissions. Likewise, many infants who have been exposed to drugs in utero may appear normal at birth and initially show no overt manifestations of drug effects. Thus, the identification of the drug-exposed infant requires a high index of clinical suspicion. Conversely, analytical testing is an objective means of determining drug exposure when it may be necessary to document proof of the infant's exposure to illicit drugs. The review will discuss the different matrices that are most commonly used for testing (e.g., maternal urine, neonatal urine, meconium, and umbilical cord), the strengths and limitations for each matrix, which drugs and metabolites are appropriate for testing, the various testing methods, and the advantages and disadvantages of each method.

Pharmacokinetics of Cannabis and Its Derivatives in Animals and Humans During Pregnancy and Breastfeeding

Cannabis is one of the most widely used illicit drugs during pregnancy and lactation. With the recent legalization of cannabis in many countries, health professionals are increasingly exposed to pregnant and breastfeeding women who are consuming cannabis on a regular basis as a solution for depression, anxiety, nausea, and pain. Cannabis consumption during pregnancy can induce negative birth outcomes such as reduced birth weight and increased risk of prematurity and admission to the neonatal intensive care unit. Yet, limited information is available regarding the pharmacokinetics of cannabis in the fetus and newborn exposed during pregnancy and lactation. Indeed, the official recommendations regarding the use of cannabis during these two critical development periods lack robust pharmacokinetics data and make it difficult for health professionals to guide their patients. Many clinical studies are currently evaluating the effects of cannabis on the brain development and base their groups mostly on questionnaires. These studies should be associated with pharmacokinetics studies to assess correlations between the infant brain development and the exposure to cannabis during pregnancy and breastfeeding. Our project aims to review the available data on the pharmacokinetics of cannabinoids in adults, neonates, and animals. If the available literature is abundant in adult humans and animals, there is still a lack of published data on the exposure of pregnant and lactating women and neonates. However, some of the published information causes concerns on the exposure and the potential effects of cannabis on fetuses and neonates. The safety of cannabis use for non-medical purpose during pregnancy and breastfeeding needs to be further characterized with proper pharmacokinetic studies in humans feasible in regions where cannabis has been legalized. Given the available data, significant transfer occurs to the fetus and the breastfed newborn with a theoretical risk of accumulation of products known to be biologically active.

Can Umbilical Cord and Meconium Results Be Directly Compared? Analytical Approach Matters

Maternal drug use during pregnancy is a significant concern. Drug-exposed newborns are often born premature and may suffer from birth defects, neonatal abstinence syndrome and cognitive and developmental delays. Because of this, testing of neonatal specimens is carried out to assess fetal drug exposure during pregnancy. Umbilical cord tissue (UC) and meconium are commonly used specimens for this purpose. However, comprehensive studies comparing drug positivity rates and concentration in the two specimen types are lacking. To this end, 4,036 paired UC and meconium specimens originating from 13 states within the USA were identified, and retrospective analysis of drug positivity rates and drug concentration was performed for 31 analytes in 5 drug classes. Testing for 11-Nor-9-carboxy-tetrahydrocannabinol (THC-COOH) is a separate orderable for UC specimen at our laboratory, so a second data set was created for evaluation of this drug analyte with 2,112 paired UC and meconium specimens originating from 11 states. Testing of UC was performed by semi-quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) assays, whereas, for meconium, an immunoassay-based screening preceded LC-MS-MS confirmation tests. Results generated for UC and meconium specimens were therefore compared for a total of 32 drug analytes from 6 drug classes. Drug concentrations for analytes were higher in meconium compared to UC, with the exception of phencyclidine. Despite this, the positivity rates for individual analytes were higher in UC, with the exception of THC-COOH and cocaine. Furthermore, analysis for multidrug positivity revealed that THC-COOH and opioids were the most common multidrug combination detected in both matrices. In conclusion, this study suggests that for most drug compounds, UC was more analytically sensitive to assess neonatal drug exposure by current methodologies. Additionally, by demonstrating that meconium has higher drug concentrations for most compounds, this study sets the stage for developing more sensitive assays in meconium.

Prenatal methamphetamine-impact on the mother and child-a review

Methamphetamine (MA) is the second most commonly used illicit drug in the world, after cannabis. There are limited data on the outcomes of pregnant MA users but there is rapidly emerging evidence to suggest that they are more vulnerable, marginalized and impoverished compared with other drug-using mothers. MA use during pregnancy is associated with worse pregnancy outcomes and significantly higher rates of co-existing health and psychosocial problems. Newborn infants exposed to MA are at increased risk of perinatal complications, present differently at birth to infants exposed to other drugs of dependency such as opioids and have poorer neurological adaptation and feeding difficulties. Sparse literature from neuroimaging and cohort studies suggests that the neurocognitive deficits in MA exposed children persist, even into adulthood. Current clinical practice guidelines for the care of substance exposed pregnant women are opioid-centric with little attention paid to the consequences of prenatal MA exposure.

A Case of False-positive Amphetamine Results on Urine Toxicology Testing Secondary to Imatinib

In this case report, we describe a case of imatinib leading to a false-positive amphetamine result on urine drug testing. A 21-year-old female with chronic myelocytic leukemia and in recovery from opioid use disorder reinitiated imatinib maintenance therapy in her third trimester, after previous discontinuation at the beginning of pregnancy. Subsequently, she had multiple presumptive immunoassay-based urine drug tests that resulted positive for amphetamines. The infant's meconium testing was negative for amphetamines, as was maternal definitive testing using urine gas chromatography-mass spectrometry. She had no history of stimulant use and denied any substance use during her pregnancy. Imatinib and/or its metabolites may be responsible for cross-reactivity with urine drug immunoassays leading to a false-positive result for amphetamine.

Meconium androgens are correlated with ASD-related phenotypic traits in early childhood in a familial enriched risk cohort

BACKGROUND

Prenatal exposure to increased androgens has been suggested as a risk factor for autism spectrum disorder (ASD). This hypothesis has been examined by measurement of steroids in amniotic fluid, cord blood, saliva, and blood with mixed results.

METHODS

To provide an orthogonal measure of fetal exposure, this study used meconium, the first stool of a newborn, to measure prenatal androgen exposure from infants in the Early Autism Risk Longitudinal Investigation (EARLI). EARLI is a familial-enriched risk cohort that enrolled pregnant mothers who already had a child with an ASD diagnosis. In the younger child, we investigated the association between meconium unconjugated (u) and total (t) concentrations of major androgens testosterone (T), dehydroepiandrosterone (DHEA), and androstenedione (A4), and ASD-related traits at 12 and 36 months of age. Traits were measured at 12 months with Autism Observation Scale for Infants (AOSI) and at 36 months with total score on the Social Responsiveness Scale (SRS). One hundred and seventy children had meconium and AOSI, 140 had meconium and SRS, and 137 had meconium and both AOSI and SRS.

RESULTS

Separate robust linear regressions between each of the log-transformed androgens and log-transformed SRS scores revealed three-way interaction between sex of the child, sex of the proband, and testosterone concentration. In the adjusted analyses, t-T, u-A4, and u-DHEA (P ≤ 0.01) were positively associated with AOSI scores, while u-T (P = 0.004) and u-DHEA (P = 0.007) were positively associated with SRS total score among females with female probands (n = 10). Additionally, higher concentrations of u-T (P = 0.01) and t-T (P = 0.01) predicted higher SRS total score in males with male probands (n = 63). Limitations Since we explored three-way interactions, this resulted in a limited sample size for some analyses. This study was from an enriched-risk cohort which may limit generalizability, and this study used ASD-assessment scales as outcomes instead of diagnostic categories. Additionally, the novel use of meconium in this study limits the ability to compare the results in this cohort to others due to the paucity of research on meconium.

CONCLUSIONS

This study supports the utility of meconium for studies of endogenous fetal metabolism and suggests the sex of older siblings with autism should be considered as a biological variable in relevant studies.

Prenatal tobacco and marijuana co-use: Sex-specific influences on infant cortisol stress response

Although tobacco (TOB) and marijuana (MJ) are often co-used in pregnancy, little is known regarding the joint impact of MJ + TOB on offspring development, including the developing neuroendocrine stress system. Further, despite evidence for sex-specific impacts of prenatal exposures in preclinical models, the sex-specific impact of prenatal MJ + TOB exposure on offspring neuroendocrine regulation in humans is also unknown. In the current study, overall and sex-specific influences of MJ + TOB co-use on offspring cortisol regulation were investigated over the first postnatal month. 111 mother-infant pairs from a low-income, racially and ethnically diverse sample participated. Based on Timeline Followback data with biochemical verification, three groups were identified: (1) prenatal MJ + TOB, (2) TOB only, and (3) controls. Baseline cortisol and cortisol stress response were assessed at seven points over the first postnatal month using a handling paradigm in which saliva cortisol was assessed before, during, and following a standard neurobehavioral assessment (NICU Network Neurobehavioral Scale). A significant exposure group by offspring sex interaction emerged for baseline cortisol over the first postnatal month (p = .043); MJ + TOB-exposed males showed 35-36% attenuation of baseline cortisol levels vs. unexposed and TOB-exposed males (ps ≤ .003), while no effects of exposure emerged for females. Both MJ + TOB and TOB-exposed infants showed a 22% attenuation of cortisol stress response over the first postnatal month vs. unexposed infants (ps < .03), with evidence for sex-specific effects in exploratory analyses. Although results are preliminary, this is the first human study to investigate the impact of prenatal MJ exposure on infant cortisol and the first to reveal a sex-specific impact of prenatal MJ + TOB on cortisol regulation in humans. Future, larger-scale studies are needed to elucidate mechanisms and consequences of sex-specific effects of MJ and MJ + TOB on the developing neuroendocrine stress system.

The Association Between Antenatal Maternal Self-reported Substance Use, Maternal Characteristics, and Obstetrical Variables

BACKGROUND

Substance use disorders during pregnancy are a concern both to the public and medical community, because the negative consequences can be detrimental to both mother and the fetus. The accurate identification of prenatal drug exposure is necessary to determine appropriate medical and psychosocial intervention, and to identify risk factors that may affect outcomes for the mother and her newborn. The prevalence of prenatal drug exposure is very difficult to estimate because of flaws in all methods of identification.

OBJECTIVE

The study is designed to identify risk factors and demographic variables that contribute to nondisclosure of illicit and nonillicit substance use. In addition, this study aims to determine if nondisclosure leads to adverse neonatal outcomes.

STUDY DESIGN

Newborns delivered with a positive meconium or urine toxicology, and/or known maternal exposure to illicit and nonillicit substances, were identified. Maternal records were reviewed for disclosure of substance use during pregnancy at admission for delivery along with other medical and demographic variables. Women with antenatal prescription drug use that may alter toxicology screens were excluded from analysis. Pediatric records were also reviewed to obtain neonatal variables.

RESULTS

One hundred sixty-eight newborns were identified as having prenatal exposure to an illicit or nonillicit substance over the 4-year period. Eighty-six per cent (145/168) of women tested positive or their newborn tested positive for at least 1 illicit substance, and 49% (82/168) tested positive for multiple illicit substances. Fifty-four per cent (91/168) of women did not disclose using at least one illicit drug for which she or her newborn tested positive.With regards to maternal characteristics, there was no statistically significant difference between age (P = 0.958), parity (P = 0.300), or race (P = 0.531), and disclosure or failure to disclose about illicit drug use. However, patients who did not report prenatal illicit drug use (33/82 = 40%) were less likely (P = 0.049) to receive complete prenatal care (defined as 3 or more visits) compared with those who acknowledged their substance use (40/70 = 57%).

CONCLUSION

Substance use disorders during pregnancy are an often underestimated cause of maternal, fetal, and neonatal complications. Limited studies have examined the relationship between maternal characteristics and associated illicit or nonillicit drug use. The absence of correlation between maternal demographics and disclosure of illicit substance use demonstrates the fact that all antepartum patients are at risk for these behaviors. Furthermore, the fact that women who did not disclose their illicit drug use were less likely to seek complete prenatal care reflects the need for physicians to provide a destigmatized healthcare environment, encouraging pregnant women to disclose their substance use so they can be provided with appropriate counseling and treatment.

Prenatal tobacco and marijuana co-use: Impact on newborn neurobehavior

Tobacco and marijuana are some of the most common prenatal substance exposures worldwide. The social acceptability and political landscape of marijuana and its potency have changed dramatically in the last two decades leading to increased use by pregnant women. Despite evidence for increasing marijuana use and high rates of co-use of tobacco (TOB) and marijuana (MJ) during pregnancy, the impact of prenatal exposure to each substance is typically studied in isolation. We investigated the influence of co-exposure to TOB and MJ on infant neurobehavioral development over the first postnatal month. Participants were 111 mother-infant pairs from a low-income, diverse sample (Mean age = 25 ± 5; 54% minorities). TOB and MJ use were assessed by Timeline Followback interview with biochemical confirmation. Three groups were identified: (a) prenatal MJ + TOB, (b) prenatal TOB only, (c) controls. Newborn neurobehavior was assessed at seven time points over the first postnatal month using the NICU Network Neurobehavioral Scale. MJ + TOB-exposed infants showed decreased ability to self-soothe (Self-regulation) and attend to stimuli (Attention), and increased need for examiner soothing (Handling) and low motor activity (Lethargy) versus unexposed infants. Despite low levels of MJ use in MJ + TOB co-users, co-exposure was associated with nearly double the impact on infant self-soothing and need for examiner soothing versus TOB-exposure alone. Effects of MJ + TOB co-exposure appeared more pronounced for daughters than for sons. Although results are preliminary, they highlight additional risk from dual exposure to MJ + TOB vs. TOB exposure alone, particularly for daughters. Results also highlight the critical importance of investigating prenatal exposures in concert and the need for intervention efforts to address MJ co-use in pregnant TOB users.

Impact of maternal prenatal smoking on fetal to infant neurobehavioral development

Despite recent emphasis on the profound importance of the fetal environment in "programming" postnatal development, measurement of offspring development typically begins after birth. Using a novel coding strategy combining direct fetal observation via ultrasound and actocardiography, we investigated the impact of maternal smoking during pregnancy (MSDP) on fetal neurobehavior; we also investigated links between fetal and infant neurobehavior. Participants were 90 pregnant mothers and their infants (52 MSDP-exposed; 51% minorities; ages 18-40). Fetal neurobehavior at baseline and in response to vibro-acoustic stimulus was assessed via ultrasound and actocardiography at M = 35 weeks gestation and coded via the Fetal Neurobehavioral Assessment System (FENS). After delivery, the NICU Network Neurobehavioral Scale was administered up to seven times over the first postnatal month. MSDP was associated with increased fetal activity and fetal limb movements. Fetal activity, complex body movements, and cardiac-somatic coupling were associated with infants' ability to attend to stimuli and to self-regulate over the first postnatal month. Furthermore, differential associations emerged by MSDP group between fetal activity, complex body movements, quality of movement, and coupling, and infant attention and self-regulation. The present study adds to a growing literature establishing the validity of fetal neurobehavioral measures in elucidating fetal programming pathways.

Historical and clinical factors associated with positive urine toxicology screening on labor and delivery

OBJECTIVE

Illicit drug use in pregnancy may lead to adverse outcomes. Although the American College of Obstetricians and Gynecologists recommends that all pregnant women be screened for substance use by questionnaire or conversation, it remains unclear how well these methods identify women with illicit drug use. Drug use may also be suspected based on clinical complications, such as fetal demise or placental abruption. There are currently no formal recommendations to guide targeted laboratory testing in women perceived to be at risk based on historical or clinical factors. Our objective was to determine which historical and clinical factors are associated with positive urine toxicology screens in women admitted to labor and delivery.

STUDY DESIGN

Historical cohort study of all women admitted to labor and delivery at our county hospital over a 5-year period (2010-2014). All patients underwent historical and clinical risk assessment and women perceived to be at increased risk of illicit drug use and who consented to testing had urine toxicology performed. We conducted a detailed chart review on all women with a positive test during this 5-year period and compared them to all women with a negative test in 2014, reporting values significant at a p-value of ≤0.05.

RESULTS

Amongst the 19,604 admissions during this period, 850 women underwent urine toxicology testing, accounting for 4.8% of all admissions. We compared the 83 women who tested positive for illicit drugs (9.8% of all women tested) to the 179 women who tested negative in 2014. Historical drug use was the factor most strongly associated with a positive test. Other historical and demographic factors associated with a positive test included single relationship status, lack of employment, lack of high school education, nulliparity and history of a prior sexually-transmitted or blood-borne infection. Regarding clinical risk factors, maternal medical complications were not associated with a positive test, and obstetrical complications, like preterm labor, were associated with a negative test.

CONCLUSIONS

A positive urine toxicology test was most strongly associated with maternal historical factors, especially known drug use. No clinical risk factor was associated with a positive test. The implications of our findings in guiding targeted laboratory testing are discussed.

Comparison of Biological Screening and Diagnostic Indicators to Detect In Utero Opiate and Cocaine Exposure Among Mother-Infant Dyads

BACKGROUND

Opioid and cocaine antenatal substance use can result in significant obstetric and pediatric health implications. Accurate detection of in utero-exposed neonates can improve patient care and health outcomes. Therefore, the effectiveness of mother-infant biological and diagnostic indicators collected at labor and delivery to provide accurate detection of in utero opiate and cocaine exposure was assessed.

METHODS

A retrospective medical chart review included 335 mother-infant dyads exposed to antenatal substances who were delivered between January 2009 and March 2014. Mother-infant dyads were a subset of a larger retrospective cohort of 560 substance-using mothers, who had a valid meconium drug screen (MDS) and anesthesia before delivery. Alternative biological and diagnostic indicators of maternal urine drug screens (UDS), maternal substance use International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes, and neonatal exposure diagnostic ICD-9-CM codes were compared against MDS. Data were analyzed using classification accuracy measures.

RESULTS

Compared with MDS, maternal UDS had the highest sensitivity [0.52, 95% confidence interval (CI), 0.39-0.65] and specificity (0.88, 95% CI, 0.79-0.97) to detect intrauterine opiate exposure. Maternal substance use diagnosis had the highest sensitivity (0.39, 95% CI, 0.16-0.61) and maternal UDS had the highest specificity (1.00, 95% CI, 0.99-1.00) to detect intrauterine cocaine exposure. Cocaine exposure had significantly higher accuracy scores across detection methods compared with opiate exposure.

CONCLUSIONS

Alternative indicators collected at delivery were ineffective at identifying in utero substance exposure, especially neonatal-exposed ICD-9-CM codes. Low sensitivity scores indicate that many exposed neonates could be misdiagnosed or left untreated. Accurate antenatal exposure identification at delivery is an important form of tertiary assessment that warrants the development of improved screening methodology and standardization of hospital biological drug testing.

Differences in testosterone and its precursors by sex of the offspring in meconium

Prenatal metabolism exerts profound effects on development. The first stool of the newborn, meconium, provides a window into the prenatal metabolic environment. The objective of this study was to examine the feasibility of meconium as a novel matrix to quantify prenatal steroid levels. We quantified parameters of analytical interest regarding the use of meconium, including sample stability. We hypothesized that meconium steroid content would differ by sex, prompting analysis of meconium to test effects of prenatal steroid metabolism. Meconium from 193 newborns enrolled in the Early Autism Risk Longitudinal Investigation (EARLI) study, including 107 males, and 86 females, were analyzed by isotope dilution-liquid chromatography-high resolution mass spectrometry (ID-LC-HRMS) while blinded to identity for testosterone (T), androstenedione (AD), and dehydroepiandrosterone (DHEA). Steroid levels were compared by sex, and investigations of potential trends resulting from sample storage or processing was conducted. The unconjugated steroid content of meconium in ng/g (mean, standard deviation) was for males: T (2.67, 8.99), AD (20.01, 28.12), DHEA (13.96, 23.57) and for females: T (0.82, 1.63), AD (22.32, 24.38), DHEA (21.06, 43.49). T was higher in meconium from males (p=0.0333), and DHEA was higher in meconium from females (p=0.0202). 6 female and 3 male T values were below the limit of detection. No extreme variability in hydration or trend in steroid levels by storage time was detected. Sexually dimorphic levels of hormones may reflect gestational differentiation, and future studies should consider meconium analysis.

Developmental and behavioral consequences of prenatal methamphetamine exposure: A review of the Infant Development, Environment, and Lifestyle (IDEAL) study

This study reviews the findings from the Infant Development, Environment, and Lifestyle (IDEAL) study, a multisite, longitudinal, prospective study designed to determine maternal outcome and child growth and developmental findings following prenatal methamphetamine exposure from birth up to age 7.5 years. These findings are presented in the context of the home environment and caregiver characteristics to determine how the drug and the environment interact to affect the outcome of these children. No neonatal abstinence syndrome requiring pharmacologic intervention was observed but heavy drug exposure was associated with increased stress responses in the neonatal period. Poorer inhibitory control was also observed in heavy methamphetamine exposed children placing them at high risk for impaired executive function. Independent of methamphetamine exposure, children with more responsive home environments to developmental and emotional needs demonstrated lower risks for internalizing and externalizing behavior.

Prenatal methamphetamine exposure and neonatal and infant neurobehavioral outcome: results from the IDEAL study

BACKGROUND

Methamphetamine (MA) use among pregnant women is an increasing problem in the United States. How MA use during pregnancy affects neonatal and infant neurobehavior is unknown.

METHODS

The Infant Development, Environment, and Lifestyle (IDEAL) study screened 34,833 subjects at 4 clinical centers. Of the subjects, 17,961 were eligible and 3705 were consented, among which 412 were enrolled for longitudinal follow-up. Exposed subjects were identified by self-report and/or gas chromatography/mass spectroscopy (GC/MS) confirmation of amphetamine and metabolites in meconium. Comparison subjects were matched (race, birth weight, maternal education, insurance), denied amphetamine use, and had a negative meconium screen. Both groups included prenatal alcohol, tobacco, and marijuana use, but excluded use of opiates, lysergic acid diethylamide, or phencyclidine. The Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scale (NNNS) was administered within the first 5 days of life and again at 1 month to 380 enrollees (185 exposed, 195 comparison). Analysis of variance (ANOVA) tested exposure effects on NNNS summary scores at birth and 1 month. General linear model (GLM) repeated-measures analysis assessed the effect of MA exposure over time on the NNNS scores with and without covariates.

RESULTS

By 1 month of age, both groups demonstrated higher quality of movement (P = .029), less lethargy (P = .001), and fewer asymmetric reflexes (P = .012), with no significant differences in NNNS scores between the exposed and comparison groups. Over the first month of life, arousal increased in exposed infants but decreased in comparison infants (P = .031) and total stress was decreased in exposed infants, with no change in comparison infants (P = .026).

CONCLUSIONS

Improvement in total stress and arousal were observed in MA-exposed newborns by 1 month of age relative to the newborn period.

Maternal smoking during pregnancy and infant stress response: test of a prenatal programming hypothesis

BACKGROUND

Maternal smoking during pregnancy (MSDP) is associated with early and long-term neurobehavioral deficits; however mechanisms remain unknown. We tested the hypothesis that MSDP programs the hypothalamic pituitary adrenocortical (HPA) axis of the offspring leading to adverse outcomes. In an intensive, prospective study, we investigated associations between MSDP and infant cortisol stress response and explored whether alterations in cortisol response were mediated by epigenetic modulation of the placental glucocorticoid receptor gene (NR3C1).

METHODS

Participants were 100 healthy mother-infant pairs (53% MSDP-exposed; 42% female) from a low income, racially/ethnically diverse sample (55% minorities). MSDP was assessed by timeline followback interview verified by saliva and meconium cotinine. Infant cortisol responses to a neurobehavioral exam were assessed seven times over the first postnatal month. Methylation of placental NR3C1 promoter exon 1F was assessed using bisulfite pyrosequencing in a subsample (n=45).

RESULTS

MSDP-exposed infants showed significantly and persistently attenuated basal and reactive cortisol levels over the first postnatal month vs. unexposed infants. Exploratory analyses revealed that MSDP was associated with altered methylation of the placental NR3C1 promoter; degree of methylation of the placental NR3C1 was associated with infant basal and reactive cortisol over the first postnatal month and mediated effects of MSDP on infant basal cortisol.

CONCLUSIONS

Results provide initial support for our hypothesis that MSDP programs offspring HPA (dys)regulation. Epigenetic regulation of placental GR may serve as a novel underlying mechanism. Results may have implications for delineating pathways to adverse outcomes from MSDP.

Use of meconium in perinatal epidemiology: potential benefits and pitfalls

PURPOSE

Meconium is a biomarker matrix that can be used to assess cumulative exposures in epidemiologic studies of prenatal risk factors. Depending on when meconium is collected, different exposure windows during pregnancy can be measured. However, little guidance exists regarding the extent to which timing of meconium collection will influence resulting effect estimates.

METHODS

We performed a simulation study of prenatal tobacco smoke exposure (assessed from meconium nicotine) and birth weight. We discuss four typical meconium collection methods capturing different exposure windows and assess the biases induced by these methods.

RESULTS

In simulations assuming that exposure to tobacco smoke only during late gestation was of etiologic relevance to birth weight, use of a meconium collection method that captured exposure windows other than late gestation resulted in biased estimates of the true nicotine-birth weight association.

CONCLUSIONS

Using meconium collection methods that do not reflect an exposure window of etiologic relevance can lead to biased results and erroneous conclusions regarding the nature of prenatal exposure-outcome associations. Understanding how prenatal exposure patterns vary across the pregnancy and exposure windows of etiologic relevance is essential in determining when and how to collect meconium for use in biomarker studies of prenatal exposure.

Risk of neurobehavioral disinhibition in prenatal methamphetamine-exposed young children with positive hair toxicology results

BACKGROUND

The objective was to evaluate the effects of prenatal methamphetamine exposure (PME) and postnatal drug exposures identified by child hair analysis on neurobehavioral disinhibition at 6.5 years of age.

METHODS

Mother-infant pairs were enrolled in the Infant Development, Environment, and Lifestyle (IDEAL) Study in Los Angeles, Honolulu, Tulsa, and Des Moines. PME was determined by maternal self-report and/or positive meconium results. At the 6.5-year follow-up visit, hair was collected and analyzed for methamphetamine, tobacco, cocaine, and cannabinoid markers. Child behavioral and executive function test scores were aggregated to evaluate child neurobehavioral disinhibition. Hierarchical linear regression models assessed the impact of PME, postnatal substances, and combined PME with postnatal drug exposures on the child's neurobehavioral disinhibition aggregate score. Past year caregiver substance use was compared with child hair results.

RESULTS

A total of 264 children were evaluated. Significantly more PME children (n = 133) had hair positive for methamphetamine/amphetamine (27.1% versus 8.4%) and nicotine/cotinine (38.3% versus 25.2%) than children without PME (n = 131). Overall, no significant differences in analyte hair concentrations were noted between groups. Significant differences in behavioral and executive function were observed between children with and without PME. No independent effects of postnatal methamphetamine or tobacco exposure, identified by positive hair test, were noted and no additional neurobehavioral disinhibition was observed in PME children with postnatal drug exposures, as compared with PME children without postnatal exposure.

CONCLUSIONS

Child hair testing offered a noninvasive means to evaluate postnatal environmental drug exposure, although no effects from postnatal drug exposure alone were seen. PME, alone and in combination with postnatal drug exposures, was associated with behavioral and executive function deficits at 6.5 years.

Development and validation of the first liquid chromatography-tandem mass spectrometry assay for simultaneous quantification of multiple antiretrovirals in meconium

A novel method for the simultaneous quantification of 16 antiretroviral (ARV) drugs and 4 metabolites in meconium was developed and validated. Quantification of 6 nucleoside/nucleotide reverse transcriptase inhibitors, 2 non-nucleoside reverse transcriptase inhibitors, 7 protease inhibitors, and 1 integrase inhibitor was achieved in 0.25 g of meconium. Specimen preparation included methanol homogenization and solid-phase extraction. Separate positive and negative polarity multiple reaction monitoring mode injections were required to achieve sufficient sensitivity. Linearity ranged from 10 to 75 ng/g up to 2500 ng/g for most analytes and 100-500 ng/g up to 25,000 ng/g for some; all correlation coefficients were ≥0.99. Extraction efficiencies from meconium were 32.8-119.5% with analytical recovery of 80.3-108.3% and total imprecision of 2.2-11.0% for all quantitative analytes. Two analytes with analytical recovery (70.0-138.5%) falling outside the 80-120% criteria range were considered semiquantitative. Matrix effects were -98.3-47.0% and -98.0-67.2% for analytes and internal standards, respectively. Analytes were stable (>75%) at room temperature for 24 h, 4 °C for 3 days, -20 °C for 3 freeze-thaw cycles over 3 days, and on the autosampler. Method applicability was demonstrated by analyzing meconium from HIV-uninfected infants born to HIV-positive mothers on ARV therapy. This method can be used as a tool to investigate the potential effects of in utero ARV exposure on childhood health and neurodevelopmental outcomes.

Co-morbidity of substance use disorder and psychopathology in women who use methamphetamine during pregnancy in the US and New Zealand

BACKGROUND

Methamphetamine (MA) abuse is a worldwide problem. Little is known about the co-morbidity of substance use disorders (SUD) and other psychiatric disorders of mothers who use MA prenatally. The Infant Development, Environment and Lifestyle (IDEAL) Study is a prospective, investigation of prenatal MA use and child outcome in the United States (US) and New Zealand (NZ). This study examined prenatal MA use and the co-morbidity of SUD and psychiatric disorders at 1-month postpartum.

METHOD

Mothers who used MA (US=127, NZ=97) were compared to a matched comparison group (US=193, NZ=110). The Substance Abuse Subtle Screening Inventory-3 was used to measure the probability of a SUD. The Brief Symptom Inventory (BSI) was used to measure the likelihood of a positive diagnosis of a psychiatric disorder.

RESULTS

In the US and NZ, MA groups had lower SES, increased single parenting, delayed prenatal care, and increased polydrug use. In the US only, MA mothers had lower income than the comparison group. MA users were 10 times more likely to have a SUD and twice as likely to meet BSI criteria for a diagnosable psychiatric disorder. In NZ, but not the US, MA users were five times more likely to have co-morbidity of both. This disparity may be due to higher quantities of prenatal alcohol use associated with increased psychiatric symptoms.

CONCLUSION

These findings suggest that addressing both substance abuse and psychiatric disorders in mothers who use MA may be required to effectively treat maternal MA use.

Prenatal methamphetamine exposure and childhood behavior problems at 3 and 5 years of age

OBJECTIVE

We evaluated behavior problems in children who were prenatally exposed to methamphetamine (MA) at ages 3 and 5 years.

METHODS

The Infant Development, Environment, and Lifestyle study, a prospective, longitudinal study of prenatal MA exposure and child outcome, enrolled subjects postpartum in Los Angeles, California; Honolulu, Hawaii; Des Moines, Iowa; and Tulsa, Oklahoma. Prenatal exposure was determined by maternal self-report and/or meconium results. Exposed and comparison groups were matched on race, birth weight, public health insurance, and education. Mothers in the comparison group denied use and had a negative meconium screen for amphetamines. Prenatal exposures to tobacco, alcohol, or marijuana occurred in both groups. At ages 3 and 5 years, 330 children (166 exposed and 164 comparison) were assessed for behavior problems by using the caregiver report on the Child Behavior Checklist. General linear mixed models were used to determine the effects of prenatal MA exposure, including heavy exposure (≥3 days per week), age, and the interaction of exposure and age on behavior problems with adjustment for other drugs of abuse and environmental risk factors.

RESULTS

MA exposure was associated with increased emotional reactivity and anxious/depressed problems at both ages and externalizing and attention-deficit/hyperactivity disorder problems by age 5 years. Heavy exposure was related to attention problems and withdrawn behavior at both ages. There were no effects of MA on the internalizing or total behavior problems scales.

CONCLUSIONS

This first report of behavior problems in patients as young as 3 years associated with MA exposure identifies an important public health problem. Continued follow-up can inform the development of preventive intervention programs.

Agreement of umbilical cord drug and cotinine levels with maternal self-report of drug use and smoking during pregnancy

OBJECTIVE

We undertook this study to assess the agreement between fetal umbilical cord drug levels and maternal self-report.

STUDY DESIGN

Cord samples were collected from 103 placentas after delivery as a subproject of the larger Pacific Research Center for Early Human Development (PRCEHD) study. These cord samples were then processed to obtain cord lysates and enzyme-linked immunosorbent assay (ELISA) performed for cotinine and illicit drugs. Levels of each of these substances were compared with clinical information.

RESULT

We found fair agreement between self-reported smoking and cotinine levels (κ = 0.26 (0.07 to 0.5)) as well as slight agreement with current drug use and positive drug levels (κ = 0.19 (-0.05 to 0.4)). Compared with maternal self-report, sensitivity of cotinine levels was 27% and specificity was 98%. Sensitivity of positive cord illicit drug levels was 32% and specificity was 85%.

CONCLUSION

Umbilical cords provide another independent measure of maternal drug use and are readily available. To our knowledge, this is the first study to measure cotinine levels in the umbilical cord tissue.

Identifying prenatal cannabis exposure and effects of concurrent tobacco exposure on neonatal growth

BACKGROUND

Cannabis is the most frequently used illicit drug among pregnant women, but data describing the effects of prenatal cannabis exposure and concurrent nicotine and cannabis exposures on neonatal growth are inconsistent. Testing of meconium, the first neonatal feces, offers objective evidence of prenatal cannabis exposure, but the relative ability of meconium testing and maternal self-report to identify affected neonates remains unclear.

METHODS

Eighty-six pregnant women provided detailed self-reports of daily cannabis and tobacco consumption throughout pregnancy. Cannabinoids and tobacco biomarkers were identified in oral fluid samples collected each trimester and quantified in meconium at birth.

RESULTS

Cannabis-using women were significantly more likely to also consume tobacco, and smoked similar numbers of cigarettes as non-cannabis-using tobacco smokers. As pregnancy progressed, fewer women smoked cannabis and those who continued to use cannabis reported smoking a smaller number of cannabis joints, but positive maternal oral fluid tests cast doubt on the veracity of some maternal self-reports. More neonates were identified as cannabis exposed by maternal self-report than meconium analysis, because many women quit cannabis use after the first or second trimester; meconium was more likely to be positive if cannabis use continued into the third trimester. Cannabis exposure was associated with decreased birth weight, reduced length, and smaller head circumference, even after data were controlled for tobacco coexposure.

CONCLUSIONS

Prenatal cannabis exposure was associated with fetal growth reduction. Meconium testing primarily identifies prenatal cannabis exposure occurring in the third trimester of gestation.

Prenatal methamphetamine exposure and neonatal neurobehavioral outcome in the USA and New Zealand

BACKGROUND

Methamphetamine (MA) use among pregnant women is a world-wide problem, but little is known of its impact on exposed infants.

DESIGN

The prospective, controlled longitudinal Infant Development, Environment and Lifestyle (IDEAL) study of prenatal MA exposure from birth to 36 months was conducted in the US and NZ. The US cohort has 183 exposed and 196 comparison infants; the NZ cohort has 85 exposed and 95 comparison infants. Exposure was determined by self-report and meconium assay with alcohol, marijuana, and tobacco exposures present in both groups. The NICU Neurobehavior Scale (NNNS) was administered within 5 days of life. NNNS summary scores were analyzed for exposure including heavy exposure and frequency of use by trimester and dose-response relationship with the amphetamine analyte.

RESULTS

MA exposure was associated with poorer quality of movement, more total stress/abstinence, physiological stress, and CNS stress with more nonoptimal reflexes in NZ but not in the USA. Heavy MA exposure was associated with lower arousal and excitability. First trimester MA use predicted more stress and third trimester use more lethargy and hypotonicity. Dose-response effects were observed between amphetamine concentration in meconium and CNS stress.

CONCLUSION

Across cultures, prenatal MA exposure was associated with a similar neurobehavioral pattern of under arousal, low tone, poorer quality of movement and increased stress.

Nicotine and metabolites in meconium as evidence of maternal cigarette smoking during pregnancy and predictors of neonatal growth deficits

INTRODUCTION

Many women continue tobacco use during pregnancy despite known adverse consequences on neonatal growth and development. Testing meconium, the first neonatal feces, for tobacco biomarkers offers objective evidence of prenatal tobacco exposure. However, relationships between the amount, frequency, and timing of cigarette smoking during gestation and tobacco biomarker meconium concentrations and neonatal outcomes are unclear.

METHODS

Eighty-seven pregnant women provided detailed self-reports of daily tobacco consumption throughout pregnancy. Nicotine, cotinine, and trans-3'-hydroxycotinine were quantified in neonatal meconium by liquid chromatography-tandem mass spectrometry.

RESULTS

Among nonsmokers, all meconium specimens were negative, whereas nearly all meconium specimens were positive if the mother self-reported tobacco use into the third trimester. Tobacco biomarker concentrations were significantly albeit weakly correlated with mean cigarettes per day in the third trimester. Reduced birth weight, gestational age, or head circumference were observed if meconium contained one or more tobacco biomarkers, but deficits did not correlate with biomarker concentrations.

CONCLUSION

While previously thought to reflect second and third trimester drug exposure, meconium appears to reliably identify only third trimester drug use. While a 10 ng/g nicotine, cotinine, or trans-3'-hydroxycotinine cutoff in meconium was previously proposed to differentiate tobacco-exposed from nonexposed or passively exposed neonates, improved maternal self-reporting techniques in this cohort suggest that a lower cutoff, equivalent to the analytic limits of quantification, is more appropriate.

New meconium biomarkers of prenatal methamphetamine exposure increase identification of affected neonates

BACKGROUND

Prenatal methamphetamine (MAMP) exposure is poorly reflected in neonatal meconium. Often, maternal self-reported MAMP use is not corroborated by positive results in amphetamines immunoassays of meconium, and even if initial test results are positive, they frequently are not confirmed for MAMP or amphetamine (AMP) by chromatographic analysis. The presence of the MAMP metabolites p-hydroxymethamphetamine (pOHMAMP), p-hydroxyamphetamine (pOHAMP), and norephedrine (NOREPH) in meconium may improve the identification of MAMP- and AMP-exposed neonates.

METHODS

Immunoassay-positive and -negative meconium samples were subjected to liquid chromatography- tandem mass spectrometric reanalysis for these recently identified metabolites.

RESULTS

pOHAMP and NOREPH were detected only when MAMP and/or AMP were present and thus do not appear to be promising biomarkers of prenatal MAMP exposure. pOHMAMP, in contrast, identified 6 additional neonates whose mothers reported MAMP exposure, yet had a meconium sample screened as negative; pOHMAMP was more likely to be present if maternal MAMP use continued into the third trimester. Although the pOHMAMP results for meconium samples corroborated the maternal self-reports, the confirmation rate for positive meconium screening results did not improve with the inclusion of these new biomarkers.

CONCLUSIONS

pOHMAMP identified additional MAMP- exposed neonates; therefore, MAMP, AMP, and pOHMAMP should be included in meconium chromatographic analyses. Maximizing the identification of MAMP-exposed children requires improvement in immunoassay screening tests to reduce false-negative and false-positive results. Additional research will help clarify which AMP-related compounds, if any, contribute to unconfirmed positive results in screening tests. Furthermore, nonamphetamine compounds endogenous to the complex meconium matrix also may cross-react, making chromatographic confirmation of screening results essential.