Alternative matrices for cocaine, heroin, and methadone in utero drug exposure detection

Hair testing applied to the assessment of in utero exposure to drugs: Critical analysis of 51 cases of the University Hospital of Verona

The work discusses the results of hair and urine testing performed in 51 cases of suspected in utero drug exposure handled at the University Hospital of Verona from 2016 to 2022. On the day of birth or the day after birth, urine from mother and newborn (UM and UN) and hair from mother (HM), newborn (HN) and father (HF), if possible, were collected. Urine underwent immunoassay and GC-MS analysis, whereas hair underwent LC-MS/MS and GC-MS/MS analysis. In 50 out of 51 cases, HM and/or HN were available. In 92% of them, hair testing resulted in a positive, often (>50% cases) for more than one class of substance. The most detected substances were cocaine, opiates, methadone and cannabinoids. Maternal segmental analysis showed a prevalent decreasing concentration trend during pregnancy in case of positivity for one class of substances, whereas, as expected, a neatly prevalent increasing trend in the case of positivity for more than one class of substances. In nine cases, HF was also available, resulting in all being positive, usually for the same classes of substances identified in HM, thus questioning parental responsibility. In 33 cases, urine samples from the mother or newborn were also collected. Of them, 27 cases (82%) tested positive, showing peri-partum drug consumption and then confirming the severity of the addiction. Hair testing showed to be a reliable diagnostic tool to investigate in utero drug exposure because of the possibility of obtaining a complete picture of maternal addictive behaviour and family background, thanks to segmental maternal hair analysis and father hair testing.

Drug exposure during pregnancy: Current understanding and approaches to measure maternal-fetal drug exposure

Prescription drug use is prevalent during pregnancy, yet there is limited knowledge about maternal-fetal safety and efficacy of this drug use because pregnant individuals have historically been excluded from clinical trials. Underrepresentation has resulted in a lack of data available to estimate or predict fetal drug exposure. Approaches to study fetal drug pharmacology are limited and must be evaluated for feasibility and accuracy. Anatomic and physiological changes throughout pregnancy fluctuate based on gestational age and can affect drug pharmacokinetics (PK) for both mother and fetus. Drug concentrations have been studied throughout different stages of gestation and at or following delivery in tissue and fluid biospecimens. Sampling amniotic fluid, umbilical cord blood, placental tissue, meconium, umbilical cord tissue, and neonatal hair present surrogate options to quantify and characterize fetal drug exposure. These sampling methods can be applied to all therapeutics including small molecule drugs, large molecule drugs, conjugated nanoparticles, and chemical exposures. Alternative approaches to determine PK have been explored, including physiologically based PK modeling, in vitro methods, and traditional animal models. These alternative approaches along with convenience sampling of tissue or fluid biospecimens can address challenges in studying maternal-fetal pharmacology. In this narrative review, we 1) present an overview of the current understanding of maternal-fetal drug exposure; 2) discuss biospecimen-guided sampling design and methods for measuring fetal drug concentrations throughout gestation; and 3) propose methods for advancing pharmacology research in the maternal-fetal population.

Intrauterine and Neonatal Exposure to Opioids: Toxicological, Clinical, and Medico-Legal Issues

Opioids have a rapid transplacental passage (i.e., less than 60 min); furthermore, symptoms characterize the maternal and fetal withdrawal syndrome. Opioid withdrawal significantly impacts the fetus, inducing worse outcomes and a risk of mortality. Moreover, neonatal abstinence syndrome (NAS) follows the delivery, lasts up to 10 weeks, and requires intensive management. Therefore, the prevention and adequate management of NAS are relevant public health issues. This review aims to summarize the most updated evidence in the literature regarding toxicological, clinical, and forensic issues of intrauterine exposure to opioids to provide a multidisciplinary, evidence-based approach for managing such issues. Further research is required to standardize testing and to better understand the distribution of opioid derivatives in each specimen type, as well as the clinically relevant cutoff concentrations in quantitative testing results. A multidisciplinary approach is required, with obstetricians, pediatricians, nurses, forensic doctors and toxicologists, social workers, addiction specialists, and politicians all working together to implement social welfare and social services for the baby when needed. The healthcare system should encourage multidisciplinary activity in this field and direct suspected maternal and neonatal opioid intoxication cases to local referral centers.

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.

Oxytocin Receptor Exon III Methylation in the Umbilical Cord Blood of Newborns With Prenatal Exposure to Crack Cocaine

BACKGROUND

Prenatal cocaine exposure (PCE) is associated with behavioral, cognitive, and social consequences in children that might persist into later development. However, there are still few data concerning epigenetic mechanisms associated with the effects of gestational cocaine exposure, particularly in human newborns.

AIMS

We investigated the effects of PCE on DNA methylation patterns of the Oxytocin Receptor (OXTR) gene in the umbilical cord blood (UCB). The relationship between UCB DNA methylation levels and the severity of the mother's cocaine use during pregnancy was also evaluated.

METHODS

In this cross-sectional study, 28 UCB samples of newborns with a history of crack cocaine exposure in utero and 30 UCB samples of non-exposed newborns (NEC) were compared for DNA methylation levels at two genomic loci located in exon III of the OXTR gene (OXTR1 and OXTR2) through pyrosequencing. Maternal psychopathology was investigated using the Mini International Neuropsychiatric Interview, and substance use characteristics and addiction severity were assessed using the Smoking and Substance Involvement Screening Test (ASSIST).

RESULTS

No differences between newborns with a history of PCE and NEC were observed in OXTR1 or OXTR2 DNA methylation levels. However, regression analyses showed that maternal addiction severity for crack cocaine use predicted OXTR1 DNA methylation in newborns.

CONCLUSION

These data suggest that OXTR methylation levels in the UCB of children are affected by the severity of maternal crack cocaine usage. Larger studies are likely to detect specific changes in DNA methylation relevant to the consequences of PCE.

Testing Unconventional Matrices to Monitor for Prenatal Exposure to Heroin, Cocaine, Amphetamines, Synthetic Cathinones, and Synthetic Opioids

BACKGROUND

The prevalence of drug use during pregnancy continues to increase despite the associated serious adverse obstetrical outcomes, including increased risk of miscarriage, fetal growth restriction, brain development impairment, neonatal abstinence syndrome, preterm delivery, and stillbirths. Monitoring drug use during pregnancy is crucial to limit prenatal exposure and provide suitable obstetrical health care. The authors reviewed published literature reporting the concentrations of common drugs of abuse and new psychoactive substances (NPS), such as synthetic cathinones and synthetic opioids, NPS, and their metabolites using unconventional matrices to identify drug use during pregnancy and improve data interpretation.

METHODS

A literature search was performed from 2010 to July 2019 using PubMed, Scopus, Web of Science scientific databases, and reports from international institutions to review recently published articles on heroin, cocaine, amphetamine, methamphetamine, synthetic cathinone, and synthetic opioid monitoring during pregnancy.

RESULTS

Meconium has been tested for decades to document prenatal exposure to drugs, but data regarding drug concentrations in amniotic fluid, the placenta, the umbilical cord, and neonatal hair are still lacking. Data on prenatal exposure to NPS are limited.

CONCLUSIONS

Maternal hair testing is the most sensitive alternative matrix for identifying drug use during pregnancy, while drug concentrations in the meconium, placenta, and umbilical cord offer the identification of prenatal drug exposure at birth. Adverse developmental outcomes for the infant make it critical to promptly identify maternal drug use to limit fetal exposure or, if determined at birth, to provide resources to the exposed child and family. Alternative matrices offer choices for monitoring and challenge laboratories to deliver highly sensitive and specific analytical methods for detection.

Monitoring Prenatal Exposure to Buprenorphine and Methadone

PURPOSE

Buprenorphine and methadone are international gold standards for managing opioid use disorders. Although they are efficacious in treating opioid dependence, buprenorphine and methadone present risks, especially during pregnancy, causing neonatal abstinence syndrome and adverse obstetrical outcomes. Buprenorphine and methadone are also abused during pregnancy, and identifying their use is important to limit unprescribed prenatal exposure. Previous studies have suggested that concentrations of buprenorphine, but not methadone markers in unconventional matrices may predict child outcomes, although currently only limited data exist. We reviewed the literature on concentrations of buprenorphine, methadone, and their metabolites in unconventional matrices to improve data interpretation.

METHODS

A literature search was conducted using scientific databases (PubMed, Scopus, Web of Science, and reports from international institutions) to review published articles on buprenorphine and methadone monitoring during pregnancy.

RESULTS

Buprenorphine and methadone and their metabolites were quantified in the meconium, umbilical cord, placenta, and maternal and neonatal hair. Methadone concentrations in the meconium and hair were typically higher than those in other matrices, although the concentrations in the placenta and umbilical cord were more suitable for predicting neonatal outcomes. Buprenorphine concentrations were lower and required sensitive instrumentation, as measuring buprenorphine glucuronidated metabolites is critical to predict neonatal outcomes.

CONCLUSIONS

Unconventional matrices are good alternatives to conventional ones for monitoring drug exposure during pregnancy. However, data are currently scarce on buprenorphine and methadone during pregnancy to accurately interpret their concentrations. Clinical studies should be conducted with larger cohorts, considering confounding factors such as illicit drug co-exposure.

Microextraction by Packed Sorbent as a Novel Strategy for Sample Clean-Up in the Determination of Methadone and EDDP in Hair

A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its primary metabolite (EDDP) in hair samples was developed. The miniaturized approach coupled to gas chromatography with tandem mass spectrometry (GC-MS-MS) was successfully validated. Hair samples (50 mg) were incubated with 1 mL of 1 M sodium hydroxide for 45 min at 50°C, time after which the extract was neutralized by adding 100 μL of 20% formic acid. Subsequently, MEPS was applied using a M1 sorbent (4 mg; 80% C8 and 20% strong cation-exchange (SCX)), first conditioned with three 250-μL cycles of methanol and three 250-μL cycles of 2% formic acid. The extract load occurred with nine 150-μL cycles followed by a washing step involving three 50-μL cycles with 3.36% formic acid. For the elution of the analytes, six 100-μL cycles of 2.36% ammonium hydroxide in methanol were applied. The method was linear from 0.01 to 5 ng/mg, for both compounds, presenting determination coefficients greater than 0.99. Precision and accuracy were in accordance with the statements of international guidelines for method validation. This new miniaturized approach allowed obtaining recoveries ranging from 73 to 109% for methadone and 84 to 110% for EDDP, proving to be an excellent alternative to classic approaches, as well as other miniaturized procedures.

Prevalence of Illicit Drug Use During Pregnancy: A Global Perspective

The World Drug Report 2019 presented an alarming figure to the world: more than 5% of the world's population has been using some type of illicit drug, and that number is growing every year. While its use increases, its abuse during pregnancy has become a global public health problem, resulting in medical and social challenges related to maternal and child health. In this context, the objective of this review was to determine the prevalence of illicit drug use during gestation across the globe, alongside with a critical review of the evaluated studies. Research was performed by simultaneously searching terms ("pregnant woman OR pregnant" OR "gestation" OR "pregnancy" AND "illicit drugs" OR "street drugs") in the databases of the Scientific Electronic Library Online, PubMed, and Web of Science. Comparisons between studies were performed in software Statistica 10.0. The data presented worrying results in relation to the variation in prevalence of illicit drug use during pregnancy, when comparing studies based on interviews or questionnaires (self-reported) (1.65%) and studies based on toxicological analysis (12.28%). In addition, we emphasize the high prevalence (5.16%) of illicit drug use among adolescent pregnant women and the low number of studies on this population. This study reveals worrying data about pregnant drug-user population, mainly the underestimation of prevalence in studies that use only questionnaires or similar methods in comparison to studies that use toxicological analysis of biological matrices. This scenario reveals necessity for health systems in different countries to establish specific public health policies for this population.

Drug testing in biological samples vs. maternal surveys for the detection of substance use during whole pregnancy

BACKGROUND

Early diagnosis of nicotine, ethanol and drug use during pregnancy is critical in order to provide adequate care. Current screening procedures show limitations in terms of reliability and short windows of detection.

OBJECTIVES

To investigate the prevalence and identify biomarkers of substance use and changes in substance use during pregnancy. To compare drug testing results in different types of biological samples (maternal hair, meconium, placenta, umbilical-cord) with self-reported data.

PARTICIPANTS AND SETTING

Prospective cohort study using data from pregnant women and their newborns.

METHODS

Biological matrices were collected at birth and analyzed by liquid chromatography tandem mass spectrometry. A paper survey was provided to determine substance use habits.

RESULTS

867 mother-newborn pairs were included. According to the analysis of biological samples, 29.1% cases were positive for one or more substances (13.6% nicotine, 8.4% ethanol, 8.3% cocaine, 6.4% cannabis, 5.7% opioids). The profile of the substance-using mother was a single woman, <28 years-old, with no higher education and unemployed. Segmental maternal hair analysis showed a decrease in tobacco, cannabis and cocaine use throughout pregnancy (p < 0.001). The level of concordance between results from interviews and from biological analyses was weak for opioids, cocaine, and cannabis (kappa coefficient < 0.40). Maternal hair detected the highest number of cases, followed by meconium and by placenta and/or umbilical-cord.

CONCLUSIONS

Maternal survey was not a reliable screening technique. Analysis of maternal hair detected the highest number of cases with the broadest detection window (whole pregnancy).

Screening for Opioid and Stimulant Exposure In Utero Through Targeted and Untargeted Metabolomics Analysis of Umbilical Cords

BACKGROUND

Neonatal abstinence syndrome is an array of signs and symptoms experienced by a newborn due to abrupt discontinuation of intrauterine exposure to certain drugs, primarily opioids. In the United States, the incidence of neonatal abstinence syndrome has tripled over the past decade. The current standard of care for drug testing includes the analysis of infant urine and meconium. Sample collection is associated with several limitations, including diaper media interferences, limited sample amount, sample heterogeneity, and the need for professional staff for collection. Umbilical cord tissue has emerged as a convenient sample matrix for testing owing to its universal availability. The purpose of this study was to examine umbilical cords using an untargeted metabolomics approach to determine the detected drugs and validate an analytical method to confirm and quantify the identified drugs.

METHODS

A metabolomics analysis was performed with 21 umbilical cords to screen for drugs and drug metabolites by liquid chromatography-mass spectrometry. Drugs were identified using the National Institute of Standards and Technology database, and an analytical method was developed and validated using secondary liquid chromatography-mass spectrometry instrument for positive confirmation and quantitative analysis.

RESULTS

Twenty-one random umbilical cords from women were tested: 4 were positive for cocaine and the primary and secondary metabolites; one was positive for methadone, the primary metabolite; 3 were positive for cotinine, the metabolite of nicotine; and 5 were positive for acetyl norfentanyl.

CONCLUSIONS

Our research is a prospective method development study using untargeted and targeted approaches to characterize steady-state drug metabolite levels in the umbilical cord matrix at the time of delivery. By characterizing drug type and concentration, this methodology can be used to develop a reliable complementary testing method for meconium toxicology screens.

The role of xenobiotic-metabolizing enzymes in the placenta: a growing research field

Introduction: The placenta is a temporary and unique organ that allows for the physical connection between a mother and fetus; this organ regulates the transport of gases and nutrients mediating the elimination of waste products contained in the fetal circulation. The placenta performs metabolic and excretion functions, on the basis of multiple enzymatic systems responsible for the oxidation, reduction, hydrolysis, and conjugation of xenobiotics. These mechanisms give the placenta a protective role that limits the fetal exposure to harmful compounds. During pregnancy, some diseases require uninterrupted treatment even if it is detrimental to the fetus. Drugs and other xenobiotics alter gene expression in the placenta with repercussions for the fetus and mother's well-being.Areas covered: This review provides a brief description of the human placental structure and function, the main drug and xenobiotic transporters and metabolizing enzymes, placenta-metabolized substrates, and alterations in gene expression that the exposure to xenobiotics may cause.Expert opinion: Research should be focused on the identification and validation of biological markers for the assessment of the harmful effects of some drugs in pregnancy, including the evaluation of polymorphisms and methylation patterns in chorionic villous samples and/or amniotic fluid.

Alternate Matrices: Meconium, Cord Tissue, Hair, and Oral Fluid

Drug testing commonly involves serum, blood, or urine. More recently, alternative specimens for drug testing have been increasingly used for clinical and forensic toxicology. Examples include oral fluid (saliva), hair, meconium, and umbilical cord tissue. Each of these matrices has unique properties that provide advantages for certain applications. Oral fluid has easier and less invasive collection requirements than urine, the most common specimen for drug screening. Oral fluid drug testing is common in Europe and steadily gaining popularity in the United States. Hair accumulates drugs and drug metabolites and provides a much longer window of detection than blood or urine. Meconium and umbilical cord tissue each allow for assessment of prenatal drug exposure over the course of months. Limitations of these alternative matrices include need for laboratory-developed tests (exception being some oral fluid immunoassays), challenges with the specimen matrix, and incomplete understanding of drug incorporation and kinetics. This chapter briefly describes each of the above alternative specimens in terms of their utility, advantages, and limitations.

Opioid Use in Pregnant Women and Neonatal Abstinence Syndrome-A Review of the Literature

Opiate use during pregnancy has been an increasing problem over the last two decades, making it an important social and health concern. The use of such substances may have serious negative outcomes in the newborn, and clinical and cognitive conditions have been reported, including neonatal abstinence syndrome, developmental problems, and lower cognitive performance. These conditions are common when opiates are used during pregnancy, making the prescription of these kinds of drugs problematic. Moreover, the mother may develop opiate addiction, thus, increasing the likelihood of the infant being born with any of those conditions. This paper reviews the use of opiates during pregnancy and focuses mainly on the neonatal abstinence syndrome. First, the commonly prescribed opiates will be identified, namely those usually involved in cases of addiction and/or neonatal abstinence syndrome. Second, published approaches to deal with those problems will be presented and discussed, including the treatment of both the mother and the infant. Finally, we will outline the treatments that are safest and most efficient, and will define future goals, approaches, and research directions for the scientific community regarding this problem.

Umbilical Cord Tissue and Meconium May Not Be Equivalent for Confirming in Utero Substance Exposure

In a retrospective study of 501 neonates with potential in utero substance exposure, the drug detection performance of a commercially available umbilical cord tissue toxicology test was evaluated against a commercially available gold standard meconium toxicology test. Drugs detected in paired meconium and umbilical cord tissue samples were often discordant.

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.

Drug exposure during pregnancy: analytical methods and toxicological findings

Drug use during pregnancy constitutes a major preventable worldwide public health issue. Birth defects, growth retardation and neurodevelopmental disorders are associated with tobacco, alcohol or drugs of abuse exposure during pregnancy. Besides these adverse health effects, drug use during pregnancy also raises legal and social concerns. Identification and quantification of drug markers in maternal and newborn biological samples offers objective evidence of exposure and complements maternal questionnaires. We reviewed the most recent analytical methods for quantifying drugs of abuse, tobacco, alcohol and psychotropic drugs in maternal, newborn and maternal-fetal unit biological samples by gas and liquid chromatography coupled to mass spectrometry. In addition, manuscripts comparing the usefulness of different biological samples to detect drug exposure during pregnancy were reviewed.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of nicotine and its metabolites in placenta and umbilical cord

Tobacco exposure during pregnancy is associated with obstetric and fetal complications. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine nicotine, cotinine, and hydroxycotinine (OH-cotinine) in placenta (PL) and umbilical cord (UC). Specimens were homogenized in water, followed by solid-phase extraction. Chromatographic separation was performed using an Atlantis® HILIC Silica column. Detection was accomplished in electrospray in positive mode. Method validation included: linearity (5 to 1000 ng/g), accuracy (86.9 to 105.2% of target concentration in PL, and 89.1 to 105.0% in UC), imprecision (6.8 to 11.8% in PL, and 7.6 to 12.2% in UC), limits of detection (2 ng/g for cotinine and OH-cotinine, and 5 ng/g for nicotine) and quantification (5 ng/g), selectivity (no endogenous or exogenous interferences), matrix effect (-34.1 to -84.5% in PL, %CV = 9.1-24.0%; -18.9 to -84.7% in UC, %CV = 10.2-23.9%), extraction efficiency (60.7 to 131.5% in PL, and 64.1 to 134.2% in UC), and stability 72 h in the autosampler (<11.5% loss in PL, and < 13% loss in UC). The method was applied to 14 PL and UC specimens from tobacco users during pregnancy. Cotinine (6.8-312.2 ng/g in PL; 6.7-342.3 ng/g in UC) was the predominant analyte, followed by OH-cotinine ( Collapse

Key Words

• LC-MS/MS
• nicotine
• placenta
• tobacco
• umbilical cord

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Affiliation(s)

Lucía Paniagua-González Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain
Cristian Jiménez-Morigosa Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain
Elena Lendoiro Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain School of Pharmacy and Life Sciences, The Robert Gordon University, Aberdeen, UK
Marta Concheiro Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York
Angelines Cruz Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain
Manuel López-Rivadulla Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain
Ana de Castro Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain

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Comparison of umbilical cord tissue and meconium for the confirmation of in utero drug exposure

OBJECTIVES

Drug screening in neonates is traditionally performed using meconium, but cord tissue has been proposed as an alternative specimen. This study compares the detection of drugs in a large number of paired meconium and umbilical cord tissue samples from subjects at risk of in utero drug exposure.

DESIGN AND METHODS

Physician-ordered toxicology results and clinical information were collected in a retrospective review of subject medical records. All toxicology testing was performed by a national reference laboratory using a combination of immunoassays and chromatography-mass spectrometry. The comparison was limited to drugs present in both cord and meconium panels.

RESULTS

Overall agreement between cord and meconium ranged from 76% (cannabinoids) to 100% (barbiturates), but Cohen's kappa was <65% for 5 of the 6 drug classes we studied. Considering meconium as the gold standard, cord was less sensitive for the detection of 5 of the 6 drug classes, and for the detection of all 5 individual opioids. For 3 of the 5 individual opioids, the concentration of drug measured in meconium did not correlate well with qualitative detection in cord.

CONCLUSIONS

This study reveals different sensitivities of drug detection in umbilical cord tissue and meconium. For the drugs studied here, meconium provides greater sensitivity, and is likely to remain the specimen of choice when sensitivity is of greatest importance. These results can help clinicians, laboratorians, and epidemiologists to (1) select the most appropriate test to confirm a suspected drug exposure and (2) interpret discordant results when testing is performed in multiple matrices.

Bioanalysis for cocaine, opiates, methadone, and amphetamines exposure detection during pregnancy

Drug exposure during pregnancy constitutes a major legal issue and a public health concern. Drug and metabolite determination in biological matrices from mother and newborn is an objective indication of prenatal drug exposure. However, limited data are available regarding the interpretation of these analytical results in terms of window of detection and degree of exposure. We collected paired maternal hair, meconium, placenta, and umbilical cord from 727 mother-newborn dyads. We analyzed these specimens by liquid chromatography-tandem mass spectrometry for the determination of cocaine, opioids, methadone, and amphetamines, and compared the analytical results from the four different matrices. The cases were divided in non-exposure, low, and frequent exposure, based on maternal hair concentrations and segmental analysis by trimesters. For cocaine, 62 cases tested positive in hair, 9 in meconium, 6 in placenta and 7 in umbilical cord. In the case of opioids, 14 maternal hair cases were positive, 11 meconium and umbilical cord and 9 placenta samples. For methadone, 11 cases were positive in hair, 9 in meconium and 6 in placenta and umbilical cord. For amphetamines, 18 cases were positive according to maternal hair, but all meconium, placenta, and umbilical cord tested negative. Maternal hair was the most sensitive specimen to detect drug exposure during pregnancy. Meconium, placenta, and umbilical cord tested positive if hair concentrations showed frequent drug use during the whole pregnancy, especially during the third trimester. Meconium, placenta, and umbilical cord also tested positive for morphine and metabolites, if this drug was administered during labour and delivery. Copyright © 2016 John Wiley & Sons, Ltd.

Neonatal abstinence syndrome: Pharmacologic strategies for the mother and infant

Opioid use in pregnancy has increased dramatically over the past decade. Since prenatal opioid use is associated with numerous obstetrical and neonatal complications, this now has become a major public health problem. In particular, in utero opioid exposure can result in neonatal abstinence syndrome (NAS) which is a serious condition characterized by central nervous system hyperirritability and autonomic nervous system dysfunction. The present review seeks to define current practices regarding the approach to the pregnant mother and neonate with prenatal opiate exposure. Although the cornerstone of prenatal management of opioid dependence is opioid maintenance therapy, the ideal agent has yet to be definitively established. Pharmacologic management of NAS is also highly variable and may include an opioid, barbiturate, and/or α-agonist. Genetic factors appear to be associated with the incidence and severity of NAS. Establishing pharmacogenetic risk factors for the development of NAS has the potential for creating opportunities for "personalized genomic medicine" and novel, individualized therapeutic interventions.

Drug Screening in Neonates

Gestational substance exposure continues to be a significant problem. Neonates may be exposed to various substances including illicit drugs, prescription drugs, and other legal substances that are best not used during pregnancy because of their potential deleterious effects as possible teratogens or their potential to create dependence and thus withdrawal in the neonate. Screening the newborn for gestational substance exposure is important for both acute care and early intervention to promote the best possible long-term outcomes. This column provides insight into what is known about the extent of substance use by pregnant women, an overview of neonatal biologic matrices for drug testing, and a discussion of the legal implications of neonatal substance screening.

Drugs of abuse in maternal hair and paired neonatal meconium: an objective assessment of foetal exposure to gestational consumption

In a prospective sample of 80 mother-infant dyads, we investigated whether drugs of abuse in maternal hair measured during the pregnancy trimesters were also present in neonatal meconium. Principal drugs of abuse were analyzed in the three consecutive maternal hair segments and meconium samples by ultra-performance liquid chromatography tandem mass spectrometry assay. Of the 80 mothers, 32 (40%) presented one or more hair shafts with at least one of the analyzed drugs of abuse and/or its metabolites. The drug of abuse with a higher prevalence in our study population was methamphetamine: 19 mothers had methamphetamine in one or more hair segments (59.4%). The second most detected drug of abuse was cocaine; nine mothers presented cocaine in one or more hair segments (28.1%). Nineteen pregnant women consumed at least one drug of abuse during the first trimester, ten continued consuming drugs of abuse during the second trimester; and nine consumed until the end of pregnancy. Five of the nine newborns from mothers who consumed drugs during the whole pregnancy showed drugs of abuse in meconium samples. Newborns from the 23 remaining mothers with one or two hair shafts positive to drugs of abuse did not present drugs in their meconium. Indeed from these results, it seems that discontinuous and/or sporadic consumption during pregnancy could produce a negligible transplacental passage and hence negative results in meconium. Furthermore, the role of placenta in the metabolism and excretion of drugs of abuse is still to be precisely investigated. Copyright © 2015 John Wiley & Sons, Ltd.

Ultra-high-pressure liquid chromatography tandem mass spectrometry determination of antidepressant and anxiolytic drugs in neonatal meconium and maternal hair

A procedure based on ultra-high-pressure liquid chromatography tandem mass spectrometry has been developed for the determination of 22 antidepressant and anxiolytic drugs ad metabolites in the three consecutive maternal hair segments representing the pregnancy trimesters and paired neonatal meconium samples. After hair washing with methyl alcohol and diethyl ether and subsequent addition of internal standards, hair samples were treated with 500 μl VMA-T M3 reagent for 1h at 100 °C. After cooling, 100 μl M3 extract were diluted with 400 μl water and a volume of 10 μl was injected into chromatographic system. Meconium samples were firstly treated with 1 ml methyl alcohol and the organic layer back-extracted twice with 1.5 ml of a mixture of ethylacetate:hexane (80:20, v/v). Chromatographic separation was achieved at ambient temperature using a reverse-phase column and a linear gradient elution with two solvents: 0.3% formic acid in acetonitrile and 5mM ammonium formate pH 3. The mass spectrometer was operated in positive ion mode, using multiple reaction monitoring via positive electrospray ionization. The method was linear from the limit of quantification (0.05-1 ng/mg hair and 5-25 ng/g meconium depending on analyte under investigation;) to 10 ng/mg hair and 1000 ng/g meconium, with an intra- and inter-assay imprecision and inaccuracy always less than 20% and an analytical recovery between 66.6% and 95.3%, depending on the considered analyte and biological matrix. Using the validated method, 7 mothers were found positive to one or more hair segments and 5 meconium samples were found positive to one or more antidepressant and anxiolytic drugs, assessing prenatal exposure to these drugs following maternal consumption in one or more pregnancy trimesters.

Bioanalysis during pregnancy: recent advances and novel sampling strategies

Consumption of drugs of abuse, tobacco and alcohol throughout pregnancy is a serious public health problem and results in an important economic cost to the health system. Drug and/or metabolites determination in biological matrices from mother and newborn is an objective measure of in utero drug exposure. We reviewed methods published for the determination of in utero drug exposure from 2007 to 2014, with special focus on meconium, placenta, umbilical cord and newborn hair. Accurate bioanalytical procedures are essential to obtain high-quality data to perform interventions and to establish correlations between analytical measures and clinical outcomes. We included a brief overview of clinical implications of in utero drug exposure to better understand the importance of this serious health issue.

Maternal and neonatal hair and breast milk in the assessment of perinatal exposure to drugs of abuse

Perinatal exposure to one or more drugs of abuse can affect the neonate temporarily or permanently. In addition to meconium, the evaluation of perinatal exposure to drugs of abuse has been achieved by testing biological matrices coming from the newborn (neonatal hair) and from the pregnant or nursing mother (maternal hair and breast milk). These matrices have the advantage of noninvasive collection and account for a sizable time window of active and passive exposure. Sensitive and specific analytical methods are required to determine minute amounts of drugs of abuse and metabolites in these matrices. The present manuscript reviews the newest analytical methods developed to detect drugs of abuse as well as ethanol biomarkers in maternal and neonatal hair and breast milk.

Contribution of in utero drug exposure when interpreting hair results in young children

Hair specimen is necessary to complement blood and/or urine analyses as it permits differentiation of a single exposure from chronic use of a drug by segmentation of the hair for a stated growth period. Moreover, due to a frequent long delay between event and police declaration, hair can be the only solution for lack of corroborative evidence of a committed crime. With the exception of lower amount of biological material in children versus adults, there is no specific analytical problem when processing samples from children. The issue is the interpretation of the findings, with respect to the different pharmacological parameters. In some very young children, the interpretation can be complicated by potential in utero exposure. Twenty-four cases from daily practice have been reviewed. Children were less than 1 year old, hair was always longer than 4 cm and the corresponding mothers admitted having used drugs during pregnancy. Drugs involved include methadone, tramadol, diphenhydramine, diazepam, cannabis, heroin, amitriptyline and bromazepam. Analyses were achieved by hyphenated chromatographic validated procedures after hair decontamination and segmentation. The concentrations measured in the hair of children were lower than those observed in subjects using therapeutically (or illegally) these drugs. In that sense, the frequency of exposures appears as un-frequent (low level of exposure), with marked decrease in the more recent period. However, the parents denied any administration in all cases and there was no reason to suspect re-exposure after delivery and no clinical problem during the period between delivery and hair collection during regular visits to the physician was noticed. The pattern of drug distribution was similar in all these cases, low concentrations in the proximal segments and highest concentration in the distal segment (last segment). When considering the concentration in the distal segment as the 100% of the response (highest concentration), after analysis of 4 segments (irrespective of the length of the segment but longer than 1cm), it was observed the following pattern: proximal segment, 5-35% of the response; segment 2, 15-50% of the response; segment 3, 25-60% of the response; and distal segment, 100% of the response. It is proposed to consider 100% in utero contribution to the final interpretation when the ratio concentration of the proximal segment to the concentration of the distal segment is lower than 0.5. This can be applied only when the child is under 1 year old and the hair shaft length is at least 4 cm (to achieve suitable segmentation). It is important, when using this cut-off to have at least 3 or 4 segments to be able to observe the variation in drug concentrations, whatever the length of each segment (>1cm).

Incidence of prenatal alcohol exposure in Prince Edward Island: a population-based descriptive study

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is a leading preventable cause of neurodevelopmental disability in North America. The stigma associated with alcohol use and abuse during pregnancy makes it difficult to obtain information on prenatal alcohol use through self-reporting. We assessed the incidence of prenatal alcohol exposure in Prince Edward Island to facilitate future public health initiatives addressing FASD.

METHODS

Prenatal alcohol exposure was examined via population-based collection of meconium and analysis of fatty acid ethyl esters (FAEEs). Fatty acid ethyl esters are nonoxidative metabolites of ethanol that are produced in the fetus. Meconium FAEE concentrations of 2.0 nmol/g or greater are indicative of frequent prenatal alcohol exposure during the last 2 trimesters of pregnancy. Samples were collected from 1307 neonates between Nov. 8, 2010, and Nov. 8, 2011, in hospitals in PEI, or from those born to mothers who resided in PEI but gave birth in Halifax, Nova Scotia. Samples were frozen and shipped for analysis. Fatty acid ethyl esters were analyzed by gas chromatography-mass spectrometry and quantified by means of deuterated internal standards.

RESULTS

Of the 1307 samples collected, 1271 samples were successfully analyzed. Positive results for FAEEs were obtained in 3.1% (n = 39) of samples collected within the first 24 hours after birth.

INTERPRETATION

Not all neonates exposed to heavy prenatal alcohol in utero will exhibit FASD; based on current estimates of predictive value for disease by exposure, our findings suggest that 1.3% of neonates born in PEI during this 1-year period will have FASD. In its application to an entire provincial birth cohort, this study successfully implemented a public health-centred approach for evaluating population-based risk of FASD, with implications for practice across Canada.