Bioanalysis during pregnancy: recent advances and novel sampling strategies

Machine learning approaches to the identification of children affected by prenatal alcohol exposure: A narrative review

Fetal alcohol spectrum disorders (FASDs) affect at least 0.8% of the population globally. The diagnosis of FASD is uniquely complex, with a heterogeneous physical and neurobehavioral presentation that requires multidisciplinary expertise for diagnosis. Many researchers have begun to incorporate machine learning approaches into FASD research to identify children who are affected by prenatal alcohol exposure, including those with FASD. This narrative review highlights these efforts. Following an introduction to machine learning, we summarize examples from the literature of neurobehavioral screening tools and physiologic markers of exposure. We discuss individual efforts, including models that classify FASD based on parent-reported neurocognitive or behavioral questionnaires, 3D facial imaging, brain imaging, DNA methylation patterns, microRNA profiles, cardiac orienting response, and dysmorphic facial features. We highlight model performance and discuss the limitations of these approaches. We conclude by considering the scalability of these approaches and how these machine learning models, largely developed from clinical samples or highly exposed birth cohorts, may perform in the general population.

A Critical Review on the Opportunity to Use Placenta and Innovative Biomonitoring Methods to Characterize the Prenatal Chemical Exposome

Adverse effects associated with chemical exposures during pregnancy include several developmental and reproductive disorders. However, considering the tens of thousands of chemicals present on the market, the effects of chemical mixtures on the developing fetus is still likely underestimated. In this critical review, we discuss the potential to apply innovative biomonitoring methods using high-resolution mass spectrometry (HRMS) on placenta to improve the monitoring of chemical exposure during pregnancy. The physiology of the placenta and its relevance as a matrix for monitoring chemical exposures and their effects on fetal health is first outlined. We then identify several key parameters that require further investigations before placenta can be used for large-scale monitoring in a robust manner. Most critical is the need for standardization of placental sampling. Placenta is a highly heterogeneous organ, and knowledge of the intraplacenta variability of chemical composition is required to ensure unbiased and robust interindividual comparisons. Other important variables include the time of collection, the sex of the fetus, and mode of delivery. Finally, we discuss the first applications of HRMS methods on the placenta to decipher the chemical exposome and describe how the use of placenta can complement biofluids collected on the mother or the fetus.

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 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.

Toxicology as a diagnostic tool to identify the misuse of drugs in the perinatal period

The use, misuse, and abuse of substances are a continued public health concern in this country and around the world. Perinatal exposure to substances of abuse is associated with several long-term negative consequences for the neonate. Limited resources exist to assist perinatal health professionals on this very complex subject. The purpose of this document is to provide additional information about selecting monitoring protocols, the specifics of appropriate testing methodologies, and the interpretation of toxicological findings. Understanding these concepts better allows perinatal healthcare professionals to be a voice for the voiceless in order to protect and enrich lives during this unprecedented opioid epidemic.

Alternative matrices in forensic toxicology: a critical review

Purpose

The use of alternative matrices in toxicological analyses has been on the rise in clinical and forensic settings. Specimens alternative to blood and urine are useful in providing additional information regarding drug exposure and analytical benefits. The goal of this paper is to present a critical review on the most recent literature regarding the application of six common alternative matrices, i.e., oral fluid, hair, sweat, meconium, breast milk and vitreous humor in forensic toxicology.

Methods

The recent literature have been searched and reviewed for the characteristics, advantages and limitations of oral fluid, hair, sweat, meconium, breast milk and vitreous humor and its applications in the analysis of traditional drugs of abuse and novel psychoactive substances (NPS).

Results

This paper outlines the properties of six biological matrices that have been used in forensic analyses, as alternatives to whole blood and urine specimens. Each of this matrix has benefits in regards to sampling, extraction, detection window, typical drug levels and other aspects. However, theses matrices have also limitations such as limited incorporation of drugs (according to physical–chemical properties), impossibility to correlate the concentrations for effects, low levels of xenobiotics and ultimately the need for more sensitive analysis. For more traditional drugs of abuse (e.g., cocaine and amphetamines), there are already data available on the detection in alternative matrices. However, data on the determination of emerging drugs such as the NPS in alternative biological matrices are more limited.

Conclusions

Alternative biological fluids are important specimens in forensic toxicology. These matrices have been increasingly reported over the years, and this dynamic will probably continue in the future, especially considering their inherent advantages and the possibility to be used when blood or urine are unavailable. However, one should be aware that these matrices have limitations and particular properties, and the findings obtained from the analysis of these specimens may vary according to the type of matrix. As a potential perspective in forensic toxicology, the topic of alternative matrices will be continuously explored, especially emphasizing NPS.

Simultaneous determination of 137 drugs of abuse, new psychoactive substances, and novel synthetic opioids in meconium by UHPLC-QTOF

New psychoactive substances (NPS) have been introduced into the market in recent years, with new analytes reported every year. The use of these substances in women can occur at any stage of life, even in the childbearing age. Drug use during pregnancy presents significant risks for the mother and the fetus, so it is important to have tools that allow to detect prenatal exposure to these substances of abuse. Therefore, an analytical method for the determination of 137 NPS and other drugs of abuse in meconium by UHPLC-QTOF was developed and validated for semi-quantitative purpose. Linearity range, limit of detection (LOD), precision, matrix effect, selectivity, and specificity were evaluated. For all analytes, the calibration curves were studied in the ranges between 2, 10, or 50 ng/g and 750 or 1000 ng/g, (depending on the analyte) and the LOD ranged between 0.04 and 2.4 ng/g. The method was applied to 30 meconium specimens from cases in which fentanyl had been administered as epidural anesthesia at the time of delivery or cases in which the maternal hair was positive to other drug of abuse. Four meconium samples tested positive for fentanyl (range concentration = 440-750 ng/g) and two samples tested positive to acetylfentanyl (range concentration = 190-1400 ng/g).

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).

Prenatal Drinking in the Northern Plains: Differences Between American Indian and Caucasian Mothers

INTRODUCTION

Prenatal alcohol exposure is associated with adverse pregnancy outcomes such as fetal alcohol spectrum disorders. The study characterizes the pattern and risk factors of alcohol use during pregnancy for American Indian and Caucasian mothers in the Northern Plains.

METHODS

A general population of pregnant women was recruited from 5 sites, including 2,753 Caucasians and 2,124 American Indians (2006-2017). Alcohol consumption was based on self-report using a modified Timeline Followback interview, administered 3-4 times during pregnancy and 1 month postpartum. Risk for prenatal drinking was calculated using logistic regression models after controlling for demographics, reproductive history, prenatal care, mental health, and SES. The analysis was conducted in 2019.

RESULTS

More Caucasian mothers consumed alcoholic beverages during pregnancy than American Indians (63% vs 52%), whereas more American Indian mothers were binge drinkers than Caucasians (41% vs 28%). American Indian mothers had a lower risk of drinking in the second and third trimesters and postpartum, but a higher risk of binge drinking in the first trimester compared with Caucasians. Frequent relocation increased the risk of prenatal alcohol use among American Indian mothers, whereas age, marriage, income, parity, and fertility treatment affected the risk of prenatal drinking among Caucasian mothers.

CONCLUSIONS

Alcohol use was more prevalent among Caucasian mothers. Among those who consumed alcohol during pregnancy, American Indian mothers consumed larger quantities. Change of residence was found to be the sole risk factor for prenatal drinking among American Indian mothers, whereas different and multiple risk factors were found for Caucasian mothers.

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.

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.

DNA methylation as a predictor of fetal alcohol spectrum disorder

Background

Fetal alcohol spectrum disorder (FASD) is a developmental disorder that manifests through a range of cognitive, adaptive, physiological, and neurobiological deficits resulting from prenatal alcohol exposure. Although the North American prevalence is currently estimated at 2-5%, FASD has proven difficult to identify in the absence of the overt physical features characteristic of fetal alcohol syndrome. As interventions may have the greatest impact at an early age, accurate biomarkers are needed to identify children at risk for FASD. Building on our previous work identifying distinct DNA methylation patterns in children and adolescents with FASD, we have attempted to validate these associations in a different clinical cohort and to use our DNA methylation signature to develop a possible epigenetic predictor of FASD.

Methods

Genome-wide DNA methylation patterns were analyzed using the Illumina HumanMethylation450 array in the buccal epithelial cells of a cohort of 48 individuals aged 3.5-18 (24 FASD cases, 24 controls). The DNA methylation predictor of FASD was built using a stochastic gradient boosting model on our previously published dataset FASD cases and controls (GSE80261). The predictor was tested on the current dataset and an independent dataset of 48 autism spectrum disorder cases and 48 controls (GSE50759).

Results

We validated findings from our previous study that identified a DNA methylation signature of FASD, replicating the altered DNA methylation levels of 161/648 CpGs in this independent cohort, which may represent a robust signature of FASD in the epigenome. We also generated a predictive model of FASD using machine learning in a subset of our previously published cohort of 179 samples (83 FASD cases, 96 controls), which was tested in this novel cohort of 48 samples and resulted in a moderately accurate predictor of FASD status. Upon testing the algorithm in an independent cohort of individuals with autism spectrum disorder, we did not detect any bias towards autism, sex, age, or ethnicity.

Conclusion

These findings further support the association of FASD with distinct DNA methylation patterns, while providing a possible entry point towards the development of epigenetic biomarkers of FASD.

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.

Objective Measures of Prenatal Alcohol Exposure: A Systematic Review

CONTEXT

Objective measurement of prenatal alcohol exposure (PAE) is essential for identifying children at risk for adverse outcomes, including fetal alcohol spectrum disorders. Biomarkers have been advocated for use in universal screening programs, but their validity has not been comprehensively evaluated.

OBJECTIVE

To systematically review the validity of objective measures of PAE.

DATA SOURCES

Thirteen electronic databases and supplementary sources were searched for studies published between January 1990 and October 2015.

STUDY SELECTION

Eligible studies were those that evaluated the diagnostic accuracy of objective measures of PAE.

DATA EXTRACTION

Three reviewers independently verified study inclusion, quality assessments, and extracted data.

RESULTS

Twelve studies met inclusion criteria. Test performance varied widely across studies of maternal blood (4 studies; sensitivity 0%-100%, specificity 79%-100%), maternal hair (2 studies; sensitivity 19%-87%, specificity 56%-86%) maternal urine (2 studies; sensitivity 5%-15%, specificity 97%-100%), and biomarker test batteries (3 studies; sensitivity 22%-50%, specificity 56%-97%). Tests of the total concentration of 4 fatty acid ethyl esters (in meconium: 2 studies; in placenta: 1 study) demonstrated high sensitivity (82%-100%); however, specificity was variable (13%-98%).

LIMITATIONS

Risk of bias was high due to self-report reference standards and selective outcome reporting.

CONCLUSIONS

Current evidence is insufficient to support the use of objective measures of prenatal alcohol exposure in practice. Biomarkers in meconium and placenta tissue may be the most promising candidates for further large-scale population-based research.