False-Positive Meconium Test Results for Fatty Acid Ethyl Esters Secondary to Delayed Sample Collection

Assessing maternal alcohol consumption in pregnancy: comparison of confidential postnatal maternal interview and measurement of alcohol biomarkers in meconium

OBJECTIVE

Knowledge of alcohol consumption in pregnancy is important for early identification of children with fetal alcohol spectrum disorder. We investigated whether alcohol biomarkers fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium are predicted by maternal or newborn demographics and/or correlate with confidential early postnatal self-report of alcohol consumption in pregnancy.

DESIGN

Anonymised, observational population-based study.

SETTING

Inner-city maternity unit, Glasgow, UK.

PATIENTS

Singleton mother/infant dyads delivering every fourth day.

INTERVENTIONS

Mother: confidential postnatal interview. Baby: meconium sample for FAEEs and EtG.

RESULTS

840/908 mothers consented. 370 (46.4%) reported alcohol consumption in pregnancy, generally of modest amount; for 114 (13.6%) this was after 20 weeks' gestation. Alcohol consumption in later pregnancy was more commonly reported by older (31.3 vs 29.5 years) women of white British ethnicity (p<0.05); their babies were on average 118 g heavier (p=0.032). FAEEs were identified in all meconium samples; concentration was ≥600 ng/g in 39.6%. EtG concentration was ≥30 ng/g in 14.5%. Neither biomarker was associated with maternal age, body mass index or socioeconomic status but when EtG was ≥30 ng/g, the mother was less likely to identify as white British (71.3% vs 81.8%, p=0.028). Sensitivities of FAEEs ≥600 ng/g and EtG ≥30 ng/g were 43.1% and 11.6%, respectively for postnatal self-report of alcohol use in later pregnancy (specificities 60.6% and 84.8%).

CONCLUSIONS

FAEEs and EtG measured in meconium have low sensitivity and specificity for self-reported alcohol consumption after 20 weeks' gestation in an unselected Scottish population.

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.

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.

Phosphatidylethanol Levels in Postpartum Women and Their Newborns in Uruguay and Brazil

BACKGROUND

There is increasing interest in the development of newborn screening tests to identify children at risk of fetal alcohol spectrum disorder (FASD) in order to provide these children with early intervention. Phosphatidylethanol (PEth) has emerged as a potential universal newborn screening candidate.

METHODS

The aim of this report was to present the results of a study designed to compare PEth levels in 1,140 postpartum women and their newborn infants in Montevideo, Uruguay, and Sao Paulo, Brazil. Self-report alcohol use during pregnancy data was collected, along with both maternal and newborn dried blood spot samples for PEth analysis.

RESULTS

The average age and parity of the women in the sample were 26 years of age and 2.3 pregnancies. For the Uruguay sample (n = 611), 45.8% of postpartum women had PEth levels ≥ 8 ng/ml with a mean positive PEth of 43.6 ng/ml. In contrast, 86.8% of the newborns had PEth levels ≥ 8 ng/ml, with a mean positive PEth of 77.4 ng/ml. For the Brazil sample (n = 529), 33.2% of women had PEth levels ≥ 8 ng/ml with a mean positive PEth of 31 ng/ml. In contrast, 76.9% of the Brazil newborns had PEth levels ≥ 8 ng/ml and 43.9% with a mean positive PEth of 61.1 ng/ml. PEth levels were significantly higher in newborns compared with their postpartum mothers in both the Uruguay and Brazil samples. Self-reported third-trimester alcohol was 6% in the Uruguay sample and 9.1% in the Brazil sample compared with positive maternal PEth levels in 45.8% and 33.2%, respectively.

CONCLUSIONS

Clinicians may want to consider newborn PEth screening in high-risk populations where prenatal alcohol use is common. The mechanism underlying significantly higher PEth levels in newborns compared with their mothers is not known.

Quantifying fetal alcohol exposure by meconium fatty acid ethyl esters (FAEE); association with adverse fetal outcomes and population estimates of fetal alcohol exposure

Fetal Alcohol Spectrum Disorder (FASD) describes the wide range of adverse physical, behavioral and cognitive effects resulting from ethanol exposure during embryonic and fetal development. Identification of children suffering from FASD is often difficult, as abuse of ethanol during pregnancy is a heavily stigmatized behavior that receives little prenatal screening attention in routine care. Over the last 3 decades, measurement of the ethanol metabolites fatty acid ethyl esters (FAEE) has emerged as a useful tool to detect in the neonatal period fetal alcohol exposure starting from mid gestation. This review aims at updating clinicians and researchers on the validity and utility of this biological marker in two aspects: The association with adverse fetal outcomes and in generating population estimates of fetal alcohol exposure.

Prevalence of Fetal Alcohol Exposure by Analysis of Meconium Fatty Acid Ethyl Esters; A National Canadian Study

Our study aimed to estimate the prevalence of heavy fetal alcohol exposure through the analysis of meconium FAEEs as an objective biomarker of fetal exposure. We conducted a study on meconium samples collected nationwide through the Maternal-Infant Research on Environmental Chemicals (MIREC) Study Group. FAEE in meconium was quantified by an established headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME GC-MS). Out of 1315 samples collected in 10 Canadian obstetric units coast to coast between 2008-2011, the estimated prevalence of positive meconium FAEE ranged between 1.16% and 2.40%, translating into at least 1800 new cases of FASD in Canada each year. Positive maternal self- reports of heavy alcohol use were tenfold lower (0.24%). Use of meconium FAEE revealed tenfold more cases of heavy exposure to maternal drinking than did maternal reports. The use of objective measures of maternal alcohol exposure is critical in accurately estimating risks and in monitoring effective prevention of FASD.

Alkoholkonsum während der Schwangerschaft

Zusammenfassung. Kinder sind bereits im Mutterleib sensitiv für Umwelteinflüsse. Pränataler Alkoholkonsum zählt dabei zu den einflussreichsten Risikofaktoren für die frühkindliche Entwicklung. Das Ziel ist es, einen Überblick über die aktuelle Forschungslage zum Thema Alkoholkonsum während der Schwangerschaft zu geben. Darüber hinaus wird der Forschungsstand zu Belastungen und Folgeschäden für die frühkindliche Entwicklung durch pränatale Alkoholexposition, aber auch zu weiteren Risikofaktoren zusammengefasst. Es wird gezeigt, dass das Wissen um die Prävalenz für Alkoholkonsum während der Schwangerschaft sowohl für die Erforschung der Folgen als auch für das Umsetzen von präventiven Maßnahmen ausschlaggebend ist. Die Prävalenzen unterscheiden sich nicht nur regional, sondern können auch durch andere Faktoren beeinflusst werden. Es wird deutlich, dass der Risikofaktor Alkohol und dessen mögliche Auswirkungen auf die frühkindliche Entwicklung nicht isoliert, sondern in Abhängigkeit von weiteren genetischen und Umweltfaktoren betrachtet werden müssen. Denn auch Folgen von weiteren perinatalen Risikofaktoren machen sich in den ersten beiden Lebensjahren bemerkbar. Beispiele für Entwicklungsstörungen in dieser Entwicklungsspanne sind externalisierendes Verhalten und kognitive Beeinträchtigungen. Inwieweit sich perinatale Risikofaktoren jedoch auf Entwicklungsverläufe von Kindern, die durch pränatalen Alkoholkonsum belastet sind, auswirken, erfasst eine umfassende Diskussion. Diese Lücke gilt es zu schließen um das Zusammenspiel perinataler Risiken genauer zu verstehen und adäquat entgegenwirken zu können.

Determining the pattern and prevalence of alcohol consumption in pregnancy by measuring biomarkers in meconium

OBJECTIVE

To investigate the feasibility of determining the pattern and prevalence of alcohol consumption in pregnancy by measuring ethanol biomarkers in meconium.

DESIGN

Population-based observational study.

SETTING

Inner-city maternity unit in Scotland, UK.

POPULATION

Random sample of singleton infants delivered after 36 completed weeks' gestation.

METHODS

Fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium were measured by liquid chromatography-mass spectroscopy. Samples were frozen at -20°C before analysis. Results were compared anonymously with demographic data including maternal age, parity, smoking, ethnicity and postcode and with infant gestation, birth weight and head circumference. Written informed consent was obtained from all subjects.

RESULTS

235 samples of meconium were analysed (70% of eligible babies). Only four (1%) of mothers declined to participate. FAAEs were detected in all, including four samples below the limit of quantification (10 ng/g). 98 (42%) samples had FAEE concentrations >600 ng/g. EtG was detectable in 93 (40%) samples; in 35 (15%) EtG concentration was >30 ng/g. No mother reported heavy alcohol consumption in pregnancy. FAAE concentration correlated with EtG (Pearson's coefficient; p<0.001). There was no association between either biomarker and maternal age, parity, smoking, ethnicity or postcode, or infant gestation, birth weight or head circumference.

CONCLUSION

Measurement of ethanol biomarkers in meconium is a feasible tool for determining the pattern and prevalence of alcohol consumption in pregnancy. Data suggest that at least 15% of pregnant women in the west of Scotland are consuming significant quantities of alcohol during latter pregnancy.

Fetal alcohol-spectrum disorders: identifying at-risk mothers

Fetal alcohol-spectrum disorders (FASDs) are a collection of physical and neurobehavioral disabilities caused by prenatal exposure to alcohol. To prevent or mitigate the costly effects of FASD, we must identify mothers at risk for having a child with FASD, so that we may reach them with interventions. Identifying mothers at risk is beneficial at all time points, whether prior to pregnancy, during pregnancy, or following the birth of the child. In this review, three approaches to identifying mothers at risk are explored: using characteristics of the mother and her pregnancy, using laboratory biomarkers, and using self-report assessment of alcohol-consumption risk. At present, all approaches have serious limitations. Research is needed to improve the sensitivity and specificity of biomarkers and screening instruments, and to link them to outcomes as opposed to exposure. Universal self-report screening of all women of childbearing potential should ideally be incorporated into routine obstetric and gynecologic care, followed by brief interventions, including education and personalized feedback for all who consume alcohol, and referral to treatment as indicated. Effective biomarkers or combinations of biomarkers may be used during pregnancy and at birth to determine maternal and fetal alcohol exposure. The combination of self-report and biomarker screening may help identify a greater proportion of women at risk for having a child with FASD, allowing them to access information and treatment, and empowering them to make decisions that benefit their children.

Fetal exposure to ethanol: relationship between ethyl glucuronide in maternal hair during pregnancy and ethyl glucuronide in neonatal meconium

In recent years, fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium emerged as reliable, direct biological markers for establishing gestational ethanol exposure. We investigated whether EtG in maternal hair measured during the three trimesters of pregnancy correlated with EtG and FAEEs in neonatal meconium.

In a prospective sample of 80 mother-infant dyads from Barcelona (Spain), we measured EtG and FAEE in maternal hair segments and meconium samples using a validated UHPLC-MS/MS method.

Fifty-eight (72.5%) women had EtG concentrations in the hair shafts >7 pg/mg in one or more pregnancy trimesters, and EtG and FAEEs in meconium samples were documented in 50 and 24 of their neonates, respectively. The best significant correlations (p<0.0001) were found between EtG concentration in the proximal 0–3 and 3–6 hair shaft segments corresponding to the last two pregnancy trimesters and EtG in neonatal meconium (ρ=0.609 and ρ=0.577, respectively). Using the combination of EtG in meconium ≥30 ng/g and a median of EtG >11 pg/mg in maternal hair during the second and third trimesters of pregnancy, prenatal ethanol exposure could be predicted with a sensitivity of 85.7% and specificity of 73.7%.

This study provides evidence of proven fetal exposure to ethanol during the second and third trimesters of pregnancy by linking detection of ethanol biomarkers (EtG) in maternal hair segments and EtG in neonatal meconium.

Ethylglucuronide in maternal hair as a biomarker of prenatal alcohol exposure

While direct ethanol metabolites, including ethylglucuronide (EtG), play an important role for the confirmation of prenatal alcohol exposure (PAE), their utility is often limited by their short half-lives in blood and urine. Maternal hair allows for a retrospective measure of PAE for up to several months. This study examined the validity of hair EtG (hEtG) relative to self-reporting and five other biomarkers in 85 pregnant women. Patients were recruited from a UNM prenatal clinic, which provides care to women with substance abuse and addiction disorders. The composite index, which was based on self-reported measures of alcohol use and allowed us to classify subjects into PAE (n = 42) and control (n = 43) groups, was the criterion measure used to estimate the sensitivity and specificity of hEtG. Proximal segments of hair were collected at enrollment (average 22.0 gestational weeks) and analyzed by LC-MS/MS. At the same visit, maternal blood and urine specimens were collected for analysis of GGT, %dCDT, PEth, uEtG, and uEtS. The study population included mostly opioid-dependent (80%) patients, a large proportion of ethnic minorities (75.3% Hispanic/Latina, 8.2% American Indian, 4.7% African-American), and patients with low education (48.2% < high school). The mean maternal age at enrollment was 26.7 ± 4.8 years. Hair EtG demonstrated 19% sensitivity and 86% specificity. The sensitivities of other biomarkers were comparable (5-20%) to hEtG but specificities were higher (98-100%). Hair EtG sensitivity improved when combined with other biomarkers, especially with GGT (32.5%) and PEth (27.5%). In addition, validity of hEtG improved in patients with less frequent shampooing and those who did not use hair dyes/chemical treatments. These data suggest that hEtG alone is not a sufficiently sensitive or specific biomarker to be used separately for the identification of PAE, but might be useful in a battery along with other maternal biomarkers.

Placental Fatty Acid ethyl esters are elevated with maternal alcohol use in pregnancies complicated by prematurity

The accumulation of fatty acid ethyl esters (FAEEs) in meconium of term newborns has been described as one potential biomarker of maternal alcohol use during pregnancy. FAEEs accumulate in multiple alcohol-exposed fetal tissues and in the placenta. Limited research has focused on the identification of the premature newborn exposed to alcohol in utero. We hypothesized that maternal alcohol use occurs in a significant proportion of premature deliveries and that this exposure can be detected as elevated placental FAEEs. The goals of this study were to 1) determine the prevalence of maternal alcohol use in the premature newborn and 2) investigate whether placental FAEEs could identify those newborns with fetal alcohol exposure. This prospective observational study evaluated 80 placentas from 80 women after premature delivery. Subjects were interviewed for alcohol intake and placental FAEEs were quantified via GC/MS. Receiver Operator Characteristic (ROC) Curves were generated to evaluate the ability of placental FAEEs to predict maternal drinking during pregnancy. Adjusted ROC curves were generated to adjust for gestational age, maternal smoking, and illicit drug use. 30% of the subjects admitted to drinking alcohol during pregnancy and approximately 14% answered questions indicative of problem drinking (designated AUDIT+). The specific FAEEs ethyl stearate and linoleate, as well as combinations of oleate + linoleate + linolenate (OLL) and of OLL + stearate, were significantly (p<0.05) elevated in placentas from AUDIT+ pregnancies. Adjusted ROC Curves generated areas under the curve ranging from 88–93% with negative predictive values of 97% for AUDIT+ pregnancies. We conclude that nearly one third of premature pregnancies were alcohol-exposed, and that elevated placental FAEEs hold great promise to accurately determine maternal alcohol use, particularly heavy use, in pregnancies complicated by premature delivery.

The effect of prenatal alcohol co-exposure on neonatal abstinence syndrome in infants born to mothers in opioid maintenance treatment

OBJECTIVE

This study examined the effects of prenatal alcohol exposure (PAE) on the incidence and severity of neonatal abstinence syndrome (NAS).

STUDY DESIGN

For this pilot study, 70 pregnant women on opioid maintenance therapy (OMT) were recruited from a perinatal substance abuse clinic. Subjects were categorized into three study groups based on the timing of alcohol use during pregnancy as assessed by repeated self-reported measures and a comprehensive panel of ethanol biomarkers. NAS outcomes included: duration of hospital stay, the need for pharmacological treatment of NAS, newborn age at the initiation of NAS treatment, duration of treatment and cumulative methadone dose administered.

RESULTS

The study included a large proportion of ethnic minorities (81.4% Hispanic, 5.7% American Indian), women with less than a high school education (52.2%) and unplanned pregnancy (82.9%). In multivariate analysis, PAE was not associated with NAS outcomes; however, one newborn diagnosed with fetal alcohol syndrome (FAS) demonstrated much more severe NAS compared to other PAE infants. Interestingly, 3rd trimester PAE was associated with a higher prevalence of microcephaly (62.5%) compared to the PAE abstaining group (36.8%; p = 0.08).

CONCLUSION

In this study, PAE was not associated with NAS severity; however, further examination in a larger study is needed.

Maternal and infant exposure to environmental phenols as measured in multiple biological matrices

BACKGROUND

Results of recent national surveys have shown the high prevalence of exposure to bisphenol A (BPA) and triclosan (TCS) among the general population; however biomonitoring data for pregnant women and infants are limited.

METHODS

Women (n=80) were recruited from early prenatal clinics and asked to collect urine samples multiple times during pregnancy and once 2-3 months post-partum. Samples of infant urine and meconium as well as breast milk and infant formula were also collected. Biospecimens were analyzed by GC-MS/MS for BPA, TCS and triclocarban (TCC).

RESULTS

Triclosan was detected in over 80% of the maternal urines (geometric mean (GM): 21.61 μg/L), 60% of the infant urines (GM: 2.8 μg/L), 46% of the breast milk and 80% of the meconium samples. Triclocarban was rarely detected in any of the biospecimens. Median total BPA concentrations were 1.21 and 0.24 μg/L in maternal and infant urines, respectively. Free BPA was detected in only 11% of infant urine samples. The meconium of female infants had significantly higher concentrations of total BPA and TCS than those of males, while no differences were observed in infant urine concentrations by sex.

CONCLUSIONS

We found widespread exposure among pregnant women and infants to environmental phenols, with large inter-individual variability in exposure to triclosan. These data will contribute to the risk assessment of these chemicals, especially in susceptible sub-populations.

Ethanol, Neurodevelopment, Infant and Child Health (ENRICH) prospective cohort: Study design considerations

BACKGROUND

While intervention is the leading factor in reducing long-term disabilities in children with fetal alcohol spectrum disorder (FASD), early identification of children affected by prenatal alcohol exposure (PAE) remains challenging. Deficits in higher-order cognitive domains (e.g. executive function) might be more specific to FASD than global neurodevelopmental tests, yet these functions are not developed in very young children. Measures of early sensorimotor development may provide early indications of atypical brain development during the first two years of life.

METHODS

This paper describes the novel methodology of the Ethanol, Neurodevelopment, Infant and Child Health (ENRICH) prospective cohort study of 120 maternal-infant pairs with a goal to identify early indices of functional brain impairment associated with PAE. The cohort is established by recruiting women early in pregnancy and classifying them into one of three study groups: patients on opioid-maintenance therapy who consume alcohol during pregnancy (Group 1), patients on opioid-maintenance therapy who abstain from alcohol during pregnancy (Group 2), and healthy controls (Group 3). After the initial prenatal assessment (Visit 1), patients are followed to Visit 2 occurring at delivery, and two comprehensive assessments of children at six (Visit 3) and 20 months (Visit 4) of age. ENRICH recruitment started in November 2013 and 87 women were recruited during the first year. During Year 1, the biospecimen (maternal whole blood, serum, urine, dry blood spots of a newborn) collection rate was 100% at Visit 1, and 97.6% for those who completed Visit 2.

DISCUSSION

The tiered screening approach, evaluation of confounders, neurocognitive and magneto-/electro-encephalography (MEG/EEG) outcomes, and ethical considerations are discussed.

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.

Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers

This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation.

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.

The validity of phosphatidylethanol in dried blood spots of newborns for the identification of prenatal alcohol exposure

BACKGROUND

Accurate identification of prenatal alcohol exposure (PAE) in the newborn period offers an opportunity for early identification of children at risk of future neurocognitive problems and the implementation of interventional approaches earlier in life. PAE newborn screening by measuring phosphatidylethanol in dried blood spot (PEth-DBS) cards is feasible, logistically easier, and more cost-efficient compared with other biomarkers. However, the sensitivity and specificity of this method have yet to be established.

METHODS

This prospective cohort study examined validity of PEth-DBS among 28 infants with PAE and 32 controls relative to maternal self-report and other biomarkers. Pregnant women were recruited from a University of New Mexico clinic and followed to early postpartum period. The composite index, which was based on self-reported measures of alcohol use and allowed to classify subjects into PAE and control groups, was the criterion measure used to estimate sensitivity and specificity of PEth-DBS.

RESULTS

The study included large proportions of patients representing ethnic minorities (7.4% American Indian, 81.7% Hispanic/Latina), low education (54.2% <high school), and unplanned pregnancy (90.0%). No differences in sociodemographic characteristics, smoking or illicit drug use were observed among the study groups. The sensitivity of maternal biomarkers (gamma glutamyltranspeptidase [GGT], % carbohydrate-deficient transferrin [%CDT], urine ethyl glucuronide [UEtG], urine ethyl sulfate [UEtS]) was low (<15%) reflecting a moderate chronic or intermittent binge pattern of drinking in this cohort. PEth-DBS demonstrated 100% specificity and the highest sensitivity (32.1%) compared with other biomarkers. A battery consisting of maternal direct ethanol metabolites (UEtG, UEtS, PEth) and newborn PEth-DBS increased sensitivity to 50% without a substantial drop in specificity (93.8%).

CONCLUSIONS

Newborn PEth-DBS is a highly specific biomarker and can facilitate accurate detection of PAE in conjunction with other biomarkers. Minimal invasiveness, ease of storage and transportation of DBS cards, absence of postcollection synthesis, cost savings, and potential integration with routine newborn screening are all unique advantages of this method.

Validation of a novel method to identify in utero ethanol exposure: simultaneous meconium extraction of fatty acid ethyl esters, ethyl glucuronide, and ethyl sulfate followed by LC-MS/MS quantification

Presence of fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) in meconium, the first neonatal feces, identifies maternal alcohol consumption during pregnancy. Current meconium alcohol marker assays require separate analyses for FAEE and EtG/EtS. We describe development and validation of the first quantitative liquid chromatography tandem mass spectrometry assay for 9 FAEEs, EtG, and EtS in 100 mg meconium. For the first time, these alcohol markers are analyzed in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. 100 mg meconium was homogenized in methanol and centrifuged. The supernatant was divided, and applied to two different solid phase extraction columns for optimized analyte recovery. Limits of quantification for ethyl laurate, myristate, linolenate, palmitoleate, arachidonate, linoleate, palmitate, oleate, and stearate ranged from 25-50 ng/g, with calibration curves to 2,500-5,000 ng/g. EtG and EtS linear dynamic ranges were 5-1,000 and 2.5-500 ng/g, respectively. Mean bias and between-day imprecision were <15 %. Extraction efficiencies were 51.2-96.5 %. Matrix effects ranged from -84.7 to 16.0 %, but were compensated for by matched deuterated internal standards when available. All analytes were stable (within ±20 % change from baseline) in 3 authentic positive specimens, analyzed in triplicate, after 3 freeze/thaw cycles (-20 °C). Authentic EtG and EtS also were stable after 12 h at room temperature and 72 h at 4 °C; some FAEE showed instability under these conditions, although there was large inter-subject variability. This novel method accurately detects multiple alcohol meconium markers and enables comparison of markers for maternal alcohol consumption.

[What ethanol metabolites as biological markers tell us about alcohol use]

Alcohol and tobacco related disorders are the two leading and most expensive causes of illness in central Europe. In addition to self reports and questionnaires, biomarkers are of relevance in diagnosis and therapy of alcohol use disorders. Traditional biomarkers such as gamma glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to influence of age, gender and non alcohol related diseases, among others.Direct ethanol metabolites such as ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake--EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programs, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and fetal alcohol syndrome.

Fetal alcohol spectrum disorders and fetal alcohol syndrome: the state of the art and new diagnostic tools

Ethanol consumption during pregnancy is a widespread problem which is increasing in the generation of young women. Gestational alcohol consumption causes fetal exposure to this teratogen and is associated with the onset of fetal alcohol spectrum disorders (FASD) including fetal alcohol syndrome (FAS). FASD and FAS can lead to several physical, cognitive and behavioral disabilities, whose early diagnosis is of primary importance to perform primary prevention with total abstinence from alcohol during pregnancy and secondary prevention in newborns and children for a proper follow up to reduce risk of secondary consequences. In recent years significant efforts have been made to understand the underlying mechanisms of this disease and to identify objective biological and instrumental diagnostic tools, such as exposure biomarkers in neonatal meconium and advanced magnetic resonance imaging. Nonetheless, further studies are still needed to implement our knowledge on fetal effects of ethanol, and multidisciplinary actions are necessary to raise awareness among women of childbearing age about the danger of consuming even small amounts of ethanol during pregnancy.

The feasibility and cost of neonatal screening for prenatal alcohol exposure by measuring phosphatidylethanol in dried blood spots

BACKGROUND

Accurate confirmation of prenatal alcohol exposure (PAE) is required as a diagnostic criterion for the majority of children adversely affected by PAE who do not manifest the physical features associated with fetal alcohol syndrome. A number of ethanol biomarkers have been used to assess PAE, often with suboptimal results. The purpose of this study was to evaluate the feasibility and cost of PAE screening in newborns by measuring phosphatidylethanol (PEth) in dried blood spot (DBS) cards.

METHODS

The feasibility of collecting an additional DBS card during routine newborn screening and the background prevalence of PAE were evaluated in a de-identified sample of newborn children delivered at the University of New Mexico Hospital. Electronic orders to collect DBS cards from newborns who continue to bleed after the routine newborn screen, glucose, or hematocrit testing were initiated for all infants delivered during a 4-week time frame. Specimens were sent to a contract laboratory for PEth analysis by liquid chromatography-tandem mass spectrometry. A cost analysis was conducted to compare the cost of PAE screening by PEth in DBS versus PEth in conventional blood specimens and by meconium fatty acid ethyl esters.

RESULTS

From 230 collected cards, 201 (87.4%) had at least 1 full blood spot (amount sufficient for PEth analysis), and 6.5% had PEth >20 ng/ml indicative of potential PAE in late pregnancy. PAE screening by PEth in DBS is logistically simpler and less expensive compared with 2 other screening approaches.

CONCLUSIONS

These results indicate that screening for PAE in DBS cards is a feasible procedure and that a majority of infants have enough blood after the routine heel prick to fill an additional card. Moreover, screening by PEth analysis from DBS cards is cost-efficient. The acceptability of such screening by parents and corresponding ethical issues remain to be investigated.

Synthesis of fatty acid ethyl esters in mammalian tissues after ethanol exposure: a systematic review of the literature

The ability to undergo non-oxidative metabolism from ethanol to fatty acid ethyl esters (FAEEs) varies greatly among tissues and organs. To gain a greater understanding of non-oxidative ethanol metabolism to FAEE, we aimed to collect all published data on FAEE synthesis in mammalian organs and tissues to identify all tissues, organs, and enzymes that are known to, or likely possess FAEE-synthetic activity. A systematic search for relevant papers was performed and two independent reviewers examined potentially relevant abstracts (articles on FAEEs that pertain to ethanol exposure) to determine whether they met the inclusion criteria. Information on FAEE synthesis was retrieved from papers meeting the inclusion/exclusion criteria and summarized by organ/tissue/matrix examined. The systematic search through four databases yielded 78 articles that investigated FAEE synthesis by tissues, tissue fractions and cell lines, and 29 articles that attempted to purify and/or characterize the enzymes involved in FAEE synthesis. Two enzyme activities have been studied: FAEE synthase (FAEES, which conjugates ethanol and free fatty acid) and acyl-CoA: ethanol O-acyltransferase (AEAT, which conjugates ethanol and fatty acyl-CoA). Both activities are expressed by a variety of different enzymes. FAEES activity is the most widely studied and has been purified from several tissues and shown to be associated with several well-known enzymes, while the identity of enzymes possessing AEAT activity remains unknown. The organs and tissues that have been shown to synthesize FAEEs are discussed, with special emphasis on the studies that attempted to elucidate the enzymology of FAEE synthesis in those tissues.

Emerging biomarkers of intrauterine neonatal and pediatric exposures to xenobiotics

Biomarkers are an important tool for clinicians to detect long-term exposure to a multitude of compounds, including drugs of abuse, alcohol, and environmental toxicants. Using hair and meconium as matrices for biomarker testing provides a longer window of detection than that of blood or urine, providing clinically relevant information on prenatal exposures. The use of biomarkers can aid clinicians in early diagnosis and implementing appropriate interventions. The increasing burden of environmental toxicants has warranted the development of biomarkers for specific compounds, which could decrease exposure in humans.