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

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.

High-sensitivity neonatal urine drug testing has similar positivity rates to meconium for detecting in utero exposure to methamphetamine and cocaine

Current guidelines recommend universal screening for substance use disorders in obstetric patients, and neonatal drug testing is also frequently performed. Meconium is often the preferred specimen type to detect neonatal drug exposure due to a longer window of detection compared to urine, but most laboratories send out meconium testing to specialized reference laboratories, which can delay results for several days or more. Here, we evaluate a rapid and definitive liquid chromatography-tandem mass spectrometry method for neonatal urine drug testing and compare results obtained using this method to paired meconium drug testing in 1,424 neonates for amphetamines, cocaine, cannabinoids, opiates, oxycodone and phencyclidine. Urine testing showed equivalent sensitivity to current meconium methods for detecting in utero exposure to amphetamines and cocaine.

Can umbilical cord testing add to maternal urine drug screen for evaluation of infants at risk of neonatal opioid withdrawal syndrome?

OBJECTIVE

This study evaluated maternal urine drug screen (UDS) at delivery and umbilical cord drug testing and its association with neonatal opioid withdrawal syndrome (NOWS) diagnosis and severity following opioid exposed pregnancy.

METHODS

A retrospective chart review of 770 mother-infant dyads at five birthing hospitals in the United States Appalachian region for a five-year period was performed. Variables of interest included dyad demographics, results of maternal UDS at delivery and umbilical cord drug testing, and three neonatal outcomes: NOWS diagnosis, pharmacologic treatment administered for NOWS, and length of hospital stay (LOS) of the newborn.

RESULTS

Opioid-positivity was between 8.5% and 66.3% based on maternal UDS at delivery or umbilical cord testing. Odds of NOWS diagnosis and increased infant LOS was best associated with opioid detection in maternal UDS alone (OR = 5.62, 95% CI [3.06, 10.33] and OR = 8.33, 95% CI [3.67, 18.89], respectively). However, odds of pharmacologic treatment for NOWS was best associated with opioid detection in both maternal UDS and umbilical cord testing on the same dyad (OR = 3.22, 95% CI [1.14, 9.09]).

CONCLUSION

Maternal UDS is a better option compared to umbilical cord testing for evaluation of opioid-exposed infants and risk of NOWS diagnosis and increased infant LOS.

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.

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.

Determination of Prenatal Substance Exposure Using Meconium and Orbitrap Mass Spectrometry

The aim of this study was to develop and to validate a toxicological untargeted screening relying on LC-HRMS in meconium including the detection of the four main classes of drugs of abuse (DoA; amphetamines, cannabinoids, opioids and cocaine). The method was then applied to 29 real samples. Analyses were performed with a liquid chromatography system coupled to a benchtop Orbitrap operating in a data-dependent analysis. The sample amount was 300 mg of meconium extracted twice by solid phase extraction following two distinct procedures. Raw data were processed using the Compound Discoverer 3.2 software (Thermo). The method was evaluated and validated on 15 compounds (6-MAM, morphine, buprenorphine, norbuprenorphine, methadone, EDDP, amphetamine, MDA, MDMA, methamphetamine, cocaine, benzoylecgonine, THC, 11-OH-THC, THC-COOH). Limits of detection were between 0.5 and 5 pg/mg and limits of identification between 5 and 50 pg/mg. Mean matrix effect was between −79 and −19% (n = 6) and mean overall recovery between 18 and 73% (n = 6) at 100 pg/mg. The application allows the detection of 88 substances, including 47 pharmaceuticals and 15 pharmaceutical metabolites, cocaine and its metabolites, THC and its metabolites, and natural (morphine, codeine) and synthetic (methadone, buprenorphine, tramadol, norfentanyl) opioids. This method is now used routinely for toxicological screening in high-risk pregnancies

Assessment of biological matrices for the detection of in utero cannabis exposure

Cannabis consumption has been increasing worldwide among pregnant women. Due to the negative effects of prenatal cannabis exposure, it is necessary to develop an objective, sensitive, and specific method to determine cannabinoids use during pregnancy. In this study, we compared four different biological samples, maternal hair, meconium, umbilical cord, and placenta, for the detection of in utero cannabis exposure. The biological samples were collected from 627 mother-newborn dyads. All hair and meconium samples were analyzed, and umbilical cord and placenta if hair and/or meconium were positive for cannabinoids. Meconium and hair showed to complement each other, with an agreement between hair and meconium results of 96.7% but only 34.3% if just positive results were considered. Umbilical cord and placenta results showed a better agreement with meconium (91.3% and 92.6%, respectively) than with hair (39.1% and 34.6%, respectively). The predominant metabolites in meconium were 11-nor-carboxy-THC (THCCOOH) and 8,11-dihydroxy-THC (diOHTHC), and in umbilical cord and placenta was THCCOOH-glucuronide. Cannabidiol (CBD) and cannabinol (CBN) were detected in meconium but not in any umbilical cord or placenta. For the first time, prenatal marijuana exposure was analyzed and compared in paired hair, meconium, umbilical cord, and placental samples. Hair and meconium positivity rate was similar, but a more sensitive and specific analytical method for the hair may resolve discrepancies between the matrices. Umbilical cord and placenta may be considered suitable alternative matrices to meconium through the determination of THCCOOH-glucuronide as a biomarker of cannabis exposure.

Drug Exposure in Newborns: Effect of Selected Drugs Prescribed to Mothers During Pregnancy and Lactation

The number of newborns exposed to therapeutic drugs during pregnancy is growing because of the increased use of drugs during pregnancy. In recent years, advances in our understanding of drug placental transfer have augmented the likelihood of a healthy baby in mothers with chronic diseases needing drug therapy. Globally, for example, more than 1.4 million pregnancies in 2015 have been burdened with antiretroviral drugs due to an increasing number of HIV-positive women treated with these drugs, particularly in low- and middle-income countries. In most cases, the fetus is exposed to much higher drug doses in utero than the newborn nursed by the mother. Drug transfer through the placenta takes place by passive diffusion, active transport, or facilitated transport, and drug concentrations in the fetal circulation may be comparable to that in the mother's blood concentration. The excretion of drugs into breastmilk predominantly occurs by passive diffusion, allowing only the non-protein-bound fraction of the blood drug concentration to penetrate. Drug agencies in the United States and Europe highly recommend performing clinical trials in pregnant or breastfeeding women. However, only a few drugs have reported statistically sound data in these patient groups. Most available results concerning pregnancy are obtained from observational studies after birth, assessing outcomes in the newborn or by measuring drug concentrations in the mother and umbilical cord blood. In the case of the lactation period, some studies have evaluated drug concentrations in breastmilk and blood of the mother and/or infant. In this review, exposure to antiretrovirals, immunosuppressants used after solid organ transplantation, and antiepileptics during pregnancy and lactation has been discussed in detail.

Evaluation of Fetal Exposures to Metals and Metalloids through Meconium Analyses: A Review

This paper surveys the existing scientific literature on metals concentrations in meconium. We examine some 32 papers that analyzed meconium for aluminum, arsenic, barium, calcium, chromium, copper, iron, lithium, magnesium, manganese, zinc, lead, mercury, manganese, molybdenum, nickel, phosphorus, lead, antimony, selenium, tin, vanadium, and zinc. Because of the lack of detail in the statistics it is not possible to do a rigorous meta-analysis. What stands out is that almost every study had subjects with seemingly large amounts of at least one of the metals. The significance of metals in meconium is not clear beyond an indication of exposure although some studies have correlated metals in meconium to a number of adverse outcomes. A number of outstanding questions have been identified that, if resolved, would greatly increase the utility of meconium analysis for assessment of long-term gestational metals exposures. Among these are questions of the developmental and long-term significance of metals detected in meconium, the kinetics and interactions among metals in maternal and fetal compartments and questions on best methods for meconium analyses.

Impact of the Opioid Epidemic on Drug Testing

BACKGROUND

This review provides a description of how the opioid epidemic has impacted drug testing.

METHODS

Four major service areas of drug testing were considered, including emergency response, routine clinical care, routine forensics, and death investigations.

RESULTS

Several factors that the opioid epidemic has impacted in drug testing are discussed, including specimens, breadth of compounds recommended for testing, time to result required for specific applications, analytical approaches, interpretive support requirements, and examples of published practice guidelines.

CONCLUSIONS

Both clinical and forensic laboratories have adapted practices and developed new testing approaches to respond to the opioid epidemic. Such changes are likely to continue evolving in parallel with changes in both prescription and nonprescription opioid availability and use patterns, as well as emerging populations that are affected by the "waves" of the opioid epidemic.

Neonatal Opioid Withdrawal Syndrome

The opioid crisis has grown to affect pregnant women and infants across the United States, as evidenced by rising rates of opioid use disorder among pregnant women and neonatal opioid withdrawal syndrome among infants. Across the country, pregnant women lack access to evidence-based therapies, including medications for opioid use disorder, and infants with opioid exposure frequently receive variable care. In addition, public systems, such as child welfare and early intervention, are increasingly stretched by increasing numbers of children affected by the crisis. Systematic, enduring, coordinated, and holistic approaches are needed to improve care for the mother-infant dyad. In this statement, we provide an overview of the effect of the opioid crisis on the mother-infant dyad and provide recommendations for management of the infant with opioid exposure, including clinical presentation, assessment, treatment, and discharge.

Hospital Care of Opioid-Exposed Newborns: Clinical and Psychosocial Challenges

In the past two decades, the incidence of neonatal abstinence syndrome (NAS) has risen fivefold, mirroring the rise of opioid use disorder (OUD) among pregnant women. The resulting increases in length of stay and neonatal intensive care utilization are associated with higher hospital costs, particularly among Medicaid-financed deliveries. Pregnant women with OUD require comprehensive medical and psychosocial evaluation and management; this combined with medication-assisted treatment is critical to optimize maternal and newborn outcomes. Multidisciplinary collaboration and standardized approaches to screening for intrauterine opioid exposure, evaluation and treatment of NAS, and discharge planning are important for clinical outcomes and may improve maternal experience of care.

What the lab can and cannot do: clinical interpretation of drug testing results

Urine drug testing is one of the objective tools available to assess adherence. To monitor adherence, quantitative urinary results can assist in differentiating "new" drug use from "previous" (historical) drug use. "Spikes" in urinary concentration can assist in identifying patterns of drug use. Coupled chromatographic-mass spectrometric methods are capable of identifying very small amounts of analyte and can make clinical interpretation rather challenging, specifically for drugs that have a longer half-life. Polypharmacy is common in treatment and rehabilitation programs because of co-morbidities. Medications prescribed for comorbidities can cause drug-drug interaction and phenoconversion of genotypic extensive metabolizers into phenotypic poor metabolizers of the treatment drug. This can have significant impact on both pharmacokinetic (PK) and pharmacodynamic properties of the treatment drug. Therapeutic drug monitoring (TDM) coupled with PKs can assist in interpreting the effects of phenoconversion. TDM-PKs reflects the cumulative effects of pathophysiological changes in the patient as well as drug-drug interactions and should be considered for treatment medications/drugs used to manage pain and treat substance abuse. Since only a few enzyme immunoassays for TDM are available, this is a unique opportunity for clinical laboratory scientists to develop TDM-PK protocols that can have a significant impact on patient care and personalized medicine. Interpretation of drug screening results should be done with caution while considering pharmacological properties and the presence or absence of the parent drug and its metabolites. The objective of this manuscript is to review and address the variables that influence interpretation of different drugs analyzed from a rehabilitation and treatment programs perspective.