Determination of maternal-fetal biomarkers of prenatal exposure to ethanol: A review

Alcohol Consumption Assessed by a Biomarker and Self-Reported Drinking in a Sample of Pregnant Women in the South of Europe: A Comparative Study

(1) Background: Alcohol consumption during pregnancy is a major concern, particularly in Europe and North America. Its prevalence has so far been under-researched. In most studies, the determination of this consumption may be underestimated, as it is based on the information obtained from questionnaires rather than from biomarkers, which will provide a much more reliable approach. The main objective of this study was to compare the prevalence of consumption during pregnancy as assessed by a questionnaire and a hair biomarker. (2) Method: A cross-sectional study with a random sample of 425 pregnant women treated in public hospital consultations in Seville (Spain) and in the 20th week of their pregnancy, orally interviewed using an elaborated ad hoc questionnaire that evaluated variables of sociodemographic, obstetric, and alcohol consumption. Furthermore, the ethyl glucuronide metabolite (EtG) was tested on a hair sample in 252 pregnant women who agreed to facilitate it. Once the data obtained through the questionnaire and hair test were analyzed, the level of metabolites and self-reported alcohol consumption were compared. (3) Results: The prevalence of self-reported alcohol consumption (questionnaire) was 20.7%, and the real consumption (metabolite analysis) was 20.2%. In 16.8% of pregnant women who declared not consuming alcohol during their pregnancy, noticeable consumption was detected according to the metabolite test. No relevant level of variability in estimated alcohol consumption was detected in the biomarker with respect to the sociodemographic and obstetric variables studied. (4) Conclusions: The prevalence of alcohol consumption during pregnancy obtained through both questionnaires and metabolite analyses was similar and high. There is no association between consumption and sociodemographic factors in this sample. The determination of consumption through biomarkers allows for a more accurate approximation of the prevalence of consumption than estimated through questionnaires. Larger sample-sized studies are needed to determine consumption patterns and thus guide the adoption of more precise policies fostering abstinence from alcohol consumption since the preconception period.

Predictive risk markers in alcoholism

The medical disorders of alcoholism rank among the leading public health problems worldwide and the need for predictive and prognostic risk markers for assessing alcohol use disorders (AUD) has been widely acknowledged. Early-phase detection of problem drinking and associated tissue toxicity are important prerequisites for timely initiations of appropriate treatments and improving patient's committing to the objective of reducing drinking. Recent advances in clinical chemistry have provided novel approaches for a specific detection of heavy drinking through assays of unique ethanol metabolites, phosphatidylethanol (PEth) or ethyl glucuronide (EtG). Carbohydrate-deficient transferrin (CDT) measurements can be used to indicate severe alcohol problems. Hazardous drinking frequently manifests as heavy episodic drinking or in combinations with other unfavorable lifestyle factors, such as smoking, physical inactivity, poor diet or adiposity, which aggravate the metabolic consequences of alcohol intake in a supra-additive manner. Such interactions are also reflected in multiple disease outcomes and distinct abnormalities in biomarkers of liver function, inflammation and oxidative stress. Use of predictive biomarkers either alone or as part of specifically designed biological algorithms helps to predict both hepatic and extrahepatic morbidity in individuals with such risk factors. Novel approaches for assessing progression of fibrosis, a major determinant of prognosis in AUD, have also been made available. Predictive algorithms based on the combined use of biomarkers and clinical observations may prove to have a major impact on clinical decisions to detect AUD in early pre-symptomatic stages, stratify patients according to their substantially different disease risks and predict individual responses to treatment.

High-resolution imaging in studies of alcohol effect on prenatal development

Fetal alcohol syndrome represents the leading known preventable cause of mental retardation. FAS is on the most severe side of fetal alcohol spectrum disorders that stem from the deleterious effects of prenatal alcohol exposure. Affecting as many as 1 to 5 out of 100 children, FASD most often results in brain abnormalities that extend to structure, function, and cerebral hemodynamics. The present review provides an analysis of high-resolution imaging techniques that are used in animals and human subjects to characterize PAE-driven changes in the developing brain. Variants of magnetic resonance imaging such as magnetic resonance microscopy, magnetic resonance spectroscopy, diffusion tensor imaging, along with positron emission tomography, single-photon emission computed tomography, and photoacoustic imaging, are modalities that are used to study the influence of PAE on brain structure and function. This review briefly describes the aforementioned imaging modalities, the main findings that were obtained using each modality, and touches upon the advantages/disadvantages of each imaging approach.

Does ethyl glucuronide in hair correlate with alcohol consumption? A comparative study with other traditional biomarkers among individuals with alcohol dependence syndrome

AIM

Ethyl glucuronide (EtG) in hair is a direct biomarker proven to be useful for the detection of chronic excessive alcohol use. This study investigated the association of self-reported alcohol consumption with traditional biomarkers: GGT, AST, ALT, CDT, and MCV in blood and a direct biomarker, hair EtG, in a total of 122 patients with alcohol dependence syndrome. The diagnostic accuracy of the biomarkers to differentiate heavy from non-heavy drinkers was also evaluated.

METHOD

GGT, AST, and ALT in serum were measured by Automated Chemistry Analyzer, MCV in blood was measured by Haematology Analyzer, serum CDT was analyzed by ELISA, and EtG in hair was evaluated by gas chromatography-mass spectrometry. The association between the biomarkers and the amount of alcohol consumed (self-reported) was determined using Spearman's rank correlation.

RESULTS

All participants showed EtG level above the cut-off (0.03 ng/mg). Hair EtG showed a statistically significant linear and positive correlation with the amounts (in grams) of alcohol consumed (r = 0.60; p < 0.001). No correlation was observed among the traditional biomarkers and the quantity of alcohol consumed. Also, EtG showed an excellent receiver operating characteristic (ROC) curve (98%) with good sensitivity (85%) and specificity (60%) to classify heavy drinkers among individuals with alcohol dependence syndrome.

CONCLUSION

Hair EtG can be helpful to estimate retrospective alcohol consumption in long-term chronic alcohol consumption cases. Hair EtG also provides a reliable diagnostic test to detect heavy drinkers among individuals with alcohol dependence syndrome.

Determination of Ethyl Glucuronide and Ethyl Sulfate in Dried Blood Spots by UHPLC-MS-MS: Method Validation and Assessment of Ethanol Exposure in Postmortem Samples from Road Traffic Victims

The determination of ethyl glucuronide (EtG) and ethyl sulfate (EtS) in blood has been proposed in clinical and forensic applications to identify recent alcohol consumption. Also, there is a growing interest on the use of dried blood spots (DBS) in toxicological analysis, allowing increased stability of the analytes and simplifying sample transportation and storage. This study presents the development and validation of a method for quantifying EtG and EtS in DBS using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS). The DBS samples were extracted with a mixture of methanol and acetonitrile (80:20 v/v) and analyzed using UHPLC-MS-MS with electrospray source in negative mode, after separation with a fluoro-phenyl stationary phase. Validation was performed according to the Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines, with calibrations ranging from 0.10 to 18 µg/mL for EtG and 0.02 to 6 µg/mL for EtS. The analytes were stable in DBS stored from -20 to 45°C for 21 days. The method was successfully applied to capillary and venous DBS samples from 20 volunteers after ethanol ingestion and to DBS samples from 99 fatal victims of road traffic injuries. Capillary DBS was comparable to venous DBS and fresh whole blood in Passing-Bablok and Bland-Altman analysis, with correlation coefficients >0.91 (P < 0.001) for all comparisons. In postmortem application, the DBS EtG and EtS analysis indicated positive exposure to ethanol in 72.7% of the cases (EtG: 0.10-24.0 µg/mL and EtS: 0.03-4.11 µg/mL). The identification of ethanol consumption from blood alcohol concentrations (BACs) and EtG/EtS in DBS was in agreement in 98.6% of positive and 96.3% of negative cases (kappa 0.877, P < 0.001), indicating a high level of concordance with BAC in assessing alcohol use in postmortem samples.

Moderate alcohol consumption during pregnancy increases potency of two different drugs (the antifungal fluconazole and the antiepileptic valproate) in inducing craniofacial defects: prediction by the in vitro rat whole embryo culture

The prenatal exposure to ethanol (Eth), fluconazole (FLUCO) and sodium valproate (VPA) is related to effects on development, producing characteristic syndromic pictures. Among embryotoxic effects described for the three molecules, the alteration on craniofacial morphogenesis is a common feature in humans and animal models, including rodent embryos developed in vitro. The aim of the present work is to evaluate the developmental effects of low Eth serum concentration (17 mM, corresponding to the legal limit to drive in UK, USA, Canada, and many other countries) in mixture with increasing realistic concentrations of the antifungal drug FLUCO (62.5-500 µM) or with increasing realistic concentrations of the antiepileptic drug VPA (31.25-250 µM). Groups exposed to Eth alone (17-127.5 mM), FLUCO alone (62.5-500 µM) or VPA alone (31.25-750 µM) were also included. The chosen alternative animal model was the post-implantation rat whole embryo culture (WEC). E9.5 embryos were exposed in vitro to the test molecules during the whole test period (48 h, corresponding to the developmental stages characteristics of any vertebrate, for human embryos post-fertilization days 23-31). Data were statistically analyzed and processed for modelling applying the benchmark dose (BMD) and relative potency factor (RPF) approaches. Concentration-related effects on facial outcomes were observed in all experimental groups, with a significant enhancement in the groups co-exposed with Eth in comparison to the single exposures. Data obtained by the present work suggest an additional alert for the assumption of even low levels of alcohol in pregnant women during FLUCO or VPA therapy.

Phosphatidylethanol in Maternal or Neonatal Blood to Detect Alcohol Exposure during Pregnancy: A Systematic Review

BACKGROUND

Alcohol consumption during pregnancy, even at low doses, may damage the fetus. Pregnant women tend to underreport their alcohol consumption generating the need for sensitive and specific biomarkers, among which PEth has emerged due to its high specificity and possibility to be measured in both maternal and neonatal blood. The aim of this study is to systematically review the latest 20 years of literature for depicting the state of the art, the limitations, and the prospects of PEth for estimating alcohol consumption during pregnancy.

MATERIALS AND METHODS

A systematic search, adhering to PRISMA guidelines, of the latest 20 years of literature through "MeSH" and "free-text" protocols in the databases PubMed, SCOPUS, and Web of Science, with time limits 1 January 2002-1 March 2022, was performed. The inclusion criteria were as follows: PEth used for detecting alcohol consumption during pregnancy, quantified in blood through liquid chromatography coupled to mass spectrometry, and full texts in the English language. Opinion papers, editorials, and narrative reviews were excluded.

RESULTS

Sixteen (16) papers were included in the present review (0.81% of total retrieved records). All the included records were original articles, of which there were seven prospective cohort/longitudinal studies, six cross-sectional studies, two observational-descriptive studies, and one retrospective study. All studies assayed PEth in at least one biological matrix; seven (7) studies quantified PEth in maternal blood, seven studies in newborn blood, and only two studies in both maternal and neonatal blood. In several included papers, PEth proved more sensitive than self-reports for identifying pregnant women with an active alcohol intake with the diagnostic efficiency improving with the increase of the maternal alcohol intake.

CONCLUSIONS

Further studies, performed on wider and well-stratified populations, are needed to drive any definitive conclusion. PEth is a promising marker for monitoring alcohol use in pregnancy; however, at the present time, its use is still limited mainly by the absence of a globally agreed interpretative cut-off, the paucity of data regarding its specificity/sensitivity, and the lack of standardization on the diagnostic efficiency of the different isoforms.

Markers of Neuroinflammation in the Serum of Prepubertal Children with Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal Alcohol Spectrum Disorders (FASD) are the manifestation of the damage caused by alcohol consumption during pregnancy. Children with Fetal Alcohol Syndrome (FAS), the extreme FASD manifestation, show both facial dysmorphology and mental retardation. Alcohol consumed during gestational age prejudices brain development by reducing, among others, the synthesis and release of neurotrophic factors and neuroinflammatory markers. Alcohol drinking also induces oxidative stress.

HYPOTHESIS/OBJECTIVE

The present study aimed to investigate the potential association between neurotrophins, neuroinflammation, and oxidative stress in 12 prepubertal male and female FASD children diagnosed as FAS or partial FAS (pFAS).

METHODS

Accordingly, we analyzed, in the serum, the level of BDNF and NGF and the oxidative stress, as Free Oxygen Radicals Test (FORT) and Free Oxygen Radicals Defense (FORD). Moreover, serum levels of inflammatory mediators (IL-1α, IL-2, IL-6, IL-10, IL-12, MCP-1, TGF-β, and TNF-α) involved in neuroinflammatory and oxidative processes have been investigated.

RESULTS

We demonstrated low serum levels of NGF and BDNF in pre-pubertal FASD children with respect to healthy controls. These changes were associated with higher serum presence of TNF- α and IL-1α. Quite interestingly, an elevation in the FORD was also found despite normal FORT levels. Moreover, we found a potentiation of IL-1α, IL-2, IL-10, and IL-1α1 in the analyzed female compared to male children.

CONCLUSION

The present investigation shows an imbalance in the peripheral neuroimmune pathways that could be used in children as early biomarkers of the deficits observed in FASD.

Screening for Alcohol Use in Pregnancy: a Review of Current Practices and Perspectives

Global trends of increasing alcohol consumption among women of childbearing age, social acceptability of women's alcohol use, as well as recent changes in alcohol use patterns due to the COVID-19 pandemic may put many pregnancies at higher risk for prenatal alcohol exposure (PAE), which can cause fetal alcohol spectrum disorder (FASD). Therefore, screening of pregnant women for alcohol use has become more important than ever and should be a public health priority. This narrative review presents the state of the science on various existing prenatal alcohol use screening strategies, including the clinical utility of validated alcohol use screening instruments. It also discusses barriers for alcohol use screening in pregnancy, such as practitioner constraints, unplanned pregnancies, delayed access to prenatal care, and stigma associated with substance use in pregnancy, providing recommendations to address these barriers. By implementing consistent alcohol use screening, prenatal care providers have the opportunity to facilitate access to counseling and brief interventions and thus, to prevent new cases of FASD and improve maternal and child health.

Association of Prenatal Alcohol Exposure and Prenatal Maternal Depression with Offspring Low-Grade Inflammation in Early Adolescence

(1) This longitudinal study aimed to investigate the link between prenatal alcohol exposure and prenatal maternal depression with the offspring’s low-grade inflammatory status. (2) Prenatal alcohol exposure was determined via maternal self-report during the 3rd trimester of pregnancy (self-report+: n = 29) and the meconium alcohol metabolite Ethyl Glucuronide (EtG), collected at birth (≥30 ng/g: n = 23). The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for prenatal maternal depressive symptoms during the 3rd trimester (≥10: n = 35). Fifteen years later, 122 adolescents (M = 13.32 years; 48.4% female) provided blood samples for the analysis of high sensitivity C-reactive protein (hsCRP; M = 0.91; SD = 1.28). (3) Higher hsCRP levels were found in EtG positive adolescents (p = 0.036, ηp² = 0.04) and an inverse non-significant dose–response relation with hsCRP (r = −0.35, p = 0.113). For maternal self-reported prenatal alcohol consumption (p = 0.780, ηp² = 0.00) and prenatal depressive symptoms (p = 0.360, ηp² = 0.01) no differences for hsCRP levels between the affected and unaffected groups were found. (4) Adolescents with prenatal alcohol exposure are at risk for low-grade systemic inflammation. The EtG biomarker may be more accurate compared to self-reports. The findings suggest that prenatal maternal depression does not evoke low-grade systemic inflammation.

Phosphatidylethanol as Blood Biomarker of Alcohol Consumption in Early Pregnancy: An Observational Study in 4,067 Pregnant Women

BACKGROUND

The teratogenic effects of alcohol are well documented, but there is a lack of screening methods to detect alcohol use during pregnancy. Phosphatidylethanol 16:0/18:1 (PEth) is a specific and sensitive biomarker reflecting alcohol intake up to several weeks after consumption. The aim of this study was to investigate the prevalence of positive PEth values as an indicator of early prenatal alcohol exposure in a general population of pregnant women.

METHODS

Rhesus typing is routinely performed in Norway in all pregnancies around gestational week 12. Rhesus-negative women have an additional test taken around week 24. Blood samples submitted to St. Olav University Hospital in Trøndelag, Norway, for Rhesus typing during the period September 2017 to October 2018 were collected. A total of 4,533 whole blood samples from 4,067 women were analyzed for PEth (limit of quantification of 0.003 µM).

RESULTS

Fifty-eight women had a positive PEth sample. Of these, 50 women were positive around gestational week 12, 3 women were positive around week 24, and in 5 cases, the timing was unknown. There were no significant differences in proportions of women with positive PEth values related to age, or rural versus urban residency.

CONCLUSION

In an unselected pregnant population in Norway, 1.4% had a positive PEth sample around gestational week 12, whereas 0.4% had a positive sample around week 24. The use of PEth as an alcohol biomarker should be further investigated as a diagnostic tool in the antenatal setting.

Prenatal Alcohol Exposure and the Facial Phenotype in Adolescents: A Study Based on Meconium Ethyl Glucuronide

Here, we explore the effects of prenatal alcohol exposure (PAE) in adolescence. We investigated associations between meconium ethyl glucoronide (EtG) and facial malformation. For 129 children (66/63 male/female; M = 13.3, SD = 0.32, 12–14 years), PAE was implemented by newborn meconium EtG and maternal self-reports during the third trimester. Cognitive development was operationalized by standardized scores (WISC V). The EtG cut-off values were set at ≥10 ng/g (n = 32, 24.8% EtG10+) and ≥112 ng/g (n = 20, 15.5% EtG112+). The craniofacial shape was measured using FAS Facial Photographic Analysis Software. EtG10+− and EtG112+-affected children exhibited a shorter palpebral fissure length (p = 0.031/p = 0.055). Lip circularity was smaller in EtG112+-affected children (p = 0.026). Maternal self-reports were not associated (p > 0.164). Lip circularity correlated with fluid reasoning (EtG10+ p = 0.031; EtG112+ p = 0.298) and working memory (EtG10+ p = 0.084; EtG112+ p = 0.144). The present study demonstrates visible effects of the facial phenotype in exposed adolescents. Facial malformation was associated with a child’s cognitive performance in the alcohol-exposed group. The EtG biomarker was a better predictor than maternal self-reports.

Clinical usefulness of a urine dipstick to detect ethyl glucuronide (EtG): A quantitative clinical study in healthy young female volunteers

The metabolite of ethanol, ethyl glucuronide (EtG), reflects alcohol intake longer than ethanol and is used as a biomarker in clinical settings to detect alcohol use. We aimed to assess the clinical usefulness in a low-to-moderate alcohol intake setting and validate a new urine EtG dipstick. A three-way, open, cross-over trial was conducted. Data were collected from January to June 2019. Among 12 healthy female volunteers, we quantified urine EtG and used a dipstick following intake of either one, two or four units of alcohol. Main outcomes were concentrations of EtG in urine and serum, and creatinine and ethanol in serum. EtG in urine was determined dichotomously by dipsticks at two different thresholds and by mass spectrometry used as gold standard. EtG in urine was quantifiable up to 24 hours after alcohol intake. In some individual cases, EtG was quantifiable up to 72 hours at low concentrations. The dipstick detected EtG in urine up to 24 hours. At thresholds of 1000 and 1500 ng/mL, the dipsticks had a specificity of 100% (both), while sensitivity was 84% and 69%, respectively. The sensitivity of the dipsticks was insufficient to support a screening purpose in this setting of low-to-moderate alcohol intake.

The effect of maternal alcohol and drug abuse on first trimester screening analytes: a retrospective cohort study

Background

The purpose of this study was to determine whether first trimester trisomy screening (FTS) parameters are affected by alcohol and drug use.

Methods

A routine combined FTS including measurements of maternal serum levels of free β-human chorionic gonadotropin subunit (free β-hCG) and pregnancy-associated plasma protein A (PAPP-A) were measured at 9–11 weeks of gestation, and fetal nuchal translucency thickness (NTT) at 11–13 weeks of gestation. In total 544 women with singleton pregnancies [71 alcohol and drug abusers, 88 smokers, 168 non-smokers delivering a small for gestational age (SGA) child, and 217 unexposed control women] were assessed.

Results

Free β-hCG levels were higher in alcohol and drug abusing than in unexposed pregnant women [mean 1.5 vs. 1.2 multiples of medians (MoM); P = 0.013]. However, stepwise multiple linear regression analyses suggested that smoking could explain increased free β-hCG. Additionally, we observed lower PAPP-A levels in the smoking mothers (0.9 vs. 1.2 MoM; P = 0.045) and in those giving birth to an SGA child compared to the controls (1.1 vs.. 1.2 MoM; P < 0.001). Fetal NTT did not differ significantly between any of the groups.

Conclusions

The present study shows increased free β-hCG levels in alcohol and drug abusers, but maternal smoking may explain the result. Maternal serum PAPP-A levels were lower in smoking than non-smoking mothers, and in mothers delivering an SGA child. However, FTS parameters (PAPP-A, free β-hCG and NTT) seem not to be applicable for the use as alcohol biomarkers because of their clear overlap between alcohol abusers and healthy controls.

Fetus morphology changes by second-trimester ultrasound in pregnant women drinking alcohol

Fetal alcohol spectrum disorders (FASDs) are a group of negative conditions occurring in children exposed to alcohol during gestation. The early discovery of FASD is crucial for mother and infant follow-ups. In this study, we investigated in pregnant women the association between urine ethylglucuronide (EtG-a biomarker of alcohol drinking) and indicators of the physical characteristics of FASD by prenatal ultrasound in the second trimester of gestation. We also correlated these data with the AUDIT-C, T-ACE/TACER-3, TWEAK, and food habit diary, screening questionnaires used to disclose alcohol drinking during pregnancy. Forty-four pregnant women were randomly enrolled and examined for ultrasound investigation during the second trimester of gestation. Urine samples were provided by pregnant women immediately after the routine interviews. EtG determinations were performed with a cutoff established at 100 ng/mL, a value indicating occasional alcohol drinking. Fifteen of the enrolled pregnant women overcame the EtG cutoff (34.09%). Analysis of variance (ANOVA) revealed that the fetuses of the positive EtG pregnant women had significantly longer interorbital distance and also significantly increased frontothalamic distance (P's < 0.02). Quite interestingly, no direct correlation was found between EtG data and both food diary and AUDIT-C. However, a significant correlation was observed between urinary EtG and T-ACE (r = 0.375; P = 0.012) and between urinary EtG and TWEAK (r = 0.512; P < 0.001) and a concordance with all questionnaire for EtG values higher than 500 ng/mL. This study provides clinical evidence that the diagnosis of maternal alcohol consumption during pregnancy by urine EtG may disclose FASD-related damage in the fetus.

Multiple Tools Are Needed for the Detection of Prenatal Alcohol Exposure: Findings From a Community Antenatal Setting

BACKGROUND

Although the toxic effects of prenatal alcohol exposure (PAE) on children are well established, there is emerging evidence about the dynamics and associated demographics of drinking patterns across pregnancy, with risky drinking more likely to take place in the period before pregnancy awareness. This study investigated the use of complementary measurement tools in the understanding of alcohol use across pregnancy and reports on the rates and patterns of alcohol use in a community antenatal setting.

METHODS

Data on alcohol consumption before and after awareness of pregnancy were collected via multiple measurement tools: anonymous lifestyle questionnaire, TWEAK (Tolerance, Worried, Eye-opener, Amnesia, K/Cut down) screener questionnaire, and Substance Use Inventory interviews across multiple pregnancy timepoints. Additionally, phosphatidylethanol (PEth), a direct biomarker of alcohol metabolism, collected from newborns' dried blood spot cards, was analyzed.

RESULTS

The TWEAK screener was more likely to identify risky drinking behavior than the lifestyle questionnaire. When pregnancy was unplanned, women were more likely to find out they are pregnant significantly later (p < 0.001) and consume alcohol at moderate-heavy levels (p = 0.03), prolonging the risk to the fetus. There was an association between maternal self-reported alcohol use on the lifestyle questionnaire and Substance Use Inventory interviews, but no association between maternal reports of alcohol use and PEth results (p = 0.72). Women self-reported moderate-heavy alcohol use in early pregnancy only and a positive PEth screen indicated PAE in late pregnancy, suggesting that these methods may identify different groups of women.

CONCLUSIONS

Multiple measurement tools and methods are needed to identify PAE at different points across pregnancy. Prospective sensitive interviewing is better suited to detecting PAE in early pregnancy, but not later when social desirability bias is stronger, and the use of an objective biomarker, such a PEth, may be useful for identifying the risk of PAE in late pregnancy.

The plasma metabolome of women in early pregnancy differs from that of non-pregnant women

BACKGROUND

In comparison to the non-pregnant state, the first trimester of pregnancy is characterized by systemic adaptation of the mother. The extent to which these adaptive processes are reflected in the maternal blood metabolome is not well characterized.

OBJECTIVE

To determine the differences between the plasma metabolome of non-pregnant and pregnant women before 16 weeks gestation.

STUDY DESIGN

This study included plasma samples from 21 non-pregnant women and 50 women with a normal pregnancy (8-16 weeks of gestation). Combined measurements by ultrahigh performance liquid chromatography/tandem mass spectrometry and by gas chromatography/mass spectrometry generated molecular abundance measurements for each sample. Molecular species detected in at least 10 samples were included in the analysis. Differential abundance was inferred based on false discovery adjusted p-values (FDR) from Mann-Whitney-Wilcoxon U tests <0.1 and a minimum median abundance ratio (fold change) of 1.5. Alternatively, metabolic data were quantile normalized to remove sample-to-sample differences in the overall metabolite abundance (adjusted analysis).

RESULTS

Overall, 637 small molecules met the inclusion criteria and were tested for association with pregnancy; 44% (281/637) of small molecules had significantly different abundance, of which 81% (229/281) were less abundant in pregnant than in non-pregnant women. Eight percent (14/169) of the metabolites that remained significant in the adjusted analysis also changed as a function of gestational age. A pathway analysis revealed enrichment in steroid metabolites related to sex hormones, caffeine metabolites, lysolipids, dipeptides, and polypeptide bradykinin derivatives (all, FDR < 0.1).

CONCLUSIONS

This high-throughput mass spectrometry study identified: 1) differences between pregnant vs. non-pregnant women in the abundance of 44% of the profiled plasma metabolites, including known and novel molecules and pathways; and 2) specific metabolites that changed with gestational age.

Minocycline attenuates ethanol-induced cell death and microglial activation in the developing spinal cord

Developmental exposure to ethanol may cause fetal alcohol spectrum disorders (FASD), and the immature central nervous system (CNS) is particularly vulnerable to ethanol. In addition to vulnerability in the developing brain, we previously showed that ethanol also caused neuroapoptosis, microglial activation, and neuroinflammation in the spinal cord. Minocycline is an antibiotic that inhibits microglial activation and alleviates neuroinflammation. We sought to determine whether minocycline could protect spinal cord neurons against ethanol-induced damage. In this study, we showed that minocycline significantly inhibited ethanol-induced caspase-3 activation, microglial activation, and the expression of pro-inflammatory cytokines in the developing spinal cord. Moreover, minocycline blocked ethanol-induced activation of glycogen synthase kinase 3 beta (GSK3β), a key regulator of microglial activation. Meanwhile, minocycline significantly restored ethanol-induced inhibition of protein kinase B (AKT), mammalian target of the rapamycin (mTOR), and ERK1/2 signaling pathways, which were important pro-survival signaling pathways for neurons. Together, minocycline may attenuate ethanol-induced damage to the developing spinal cord by inhibiting microglial activation/neuroinflammation and by restoring the pro-survival signaling.

Sensitive and reliable gas chromatography tandem mass spectrometry assay for ethyl glucuronide in neonatal meconium

Prenatal exposure to maternal ethanol leads to serious physical and mental irreversible disabilities. Ethyl glucuronide (EtG) is a direct metabolite of alcohol and its measurement in neonatal meconium has been established as the best biomarker to assess prenatal exposure to social and excessive gestational ethanol. We developed and validated the first gas chromatography tandem mass spectrometry method to quantify EtG extracted from meconium by a simple solid phase extraction pretreatment. The method was linear from limit of quantification (2 ng/g) to 200 ng/g matrix with good determination coefficient (r² = 0.99). Recovery of EtG from meconium was always higher than 70% and intra-assay and inter-assay precision and accuracy were always better than 10%. Robustness of the developed GC-MS/MS method was tested by analysing 150 real samples coming from a previous national epidemiological project pre-screened through an ultra-chromatography tandem mass spectrometry assay obtaining a good comparability of results obtained by the two methods.

Quantitation of Ethyl-β-D-Glucuronide in Human Umbilical Cord Tissue by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

In utero exposure to alcohol may adversely affect the development of the embryo or fetus and result in adverse outcomes known as fetal alcohol spectrum disorders (FASD) which encompass a range of physical, behavioral, and cognitive impairments in the newborn. Since maternal self-reports are often unreliable, biomarkers of gestational alcohol consumption are necessary for accurate identification of exposed newborns at risk. Ethyl-β-D-glucuronide (EtG) is a minor phase II metabolite of ethyl alcohol (ethanol), formed by enzymatic conjugation of ethanol with glucuronic acid in the liver. As a direct biomarker for alcohol, detection of EtG in neonatal biological matrices provides accurate identification of maternal alcohol consumption and fetal alcohol exposure during pregnancy. This chapter describes the quantitation of EtG in human umbilical cord tissue by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Serum concentrations of IGF-I/IGF-II as biomarkers of alcohol damage during foetal development and diagnostic markers of Foetal Alcohol Syndrome

Foetal Alcohol Syndrome (FAS) is the most deleterious health effect derived from alcohol consumption during pregnancy and is placed at the end of the Foetal Alcohol Spectrum Disorders (FASD). Few studies have proposed potential molecular biomarkers of physical and neurological damage associated with prenatal alcohol exposure. We prospectively recruited 55 children from 8 to 12 years old, with a prenatal assessment for ethanol exposure using meconium analysis of fatty acid ethyl esters (FAEE). The control group was established for FAEE < 2 nmol/g (n = 31) and a Prenatal Ethanol Exposure (PEE) group for FAEEs > 2 nmol/g (n = 33). Moreover, 98 children adopted from Eastern European Countries (EEC) were also recruited to evaluate FASD diagnosis comprising 31 cases with complete FAS, 42 with partial FAS, 6 with ARBD and 5 with ARND. Serum values of IGF-I and IGF-II for all children recruited were determined by immunoassay. Anthropometric and neurocognitive evaluation showed severe impairments in FAS children, moderate effects in PEE and no harmful effects in the control group with no prenatal exposure to alcohol. Analysis of IGF-I and IGF-II serum concentrations revealed that FASD from EEC as well as PEE children showed significantly lower concentrations of both IGF-I and IFG-II than the control group and reference values. Moreover, Spearman correlations showed a significant effect of IGF-I on anthropometric measurements in girls, whereas IGF-II affected the neuropsychological variables in both genders. These findings validate the use of growth factors IGF-I and IGF-II as surrogate biomarkers of damage induced by prenatal exposure to ethanol and could be used in the diagnosis of foetal alcohol spectrum disorders.

Prenatal alcohol exposure prevalence as measured by direct ethanol metabolites in meconium in a Native American tribe of the southwest

BACKGROUND

Although fetal alcohol spectrum disorders represent a significant public health problem, Native Americans are underrepresented in population and targeted screening programs. Prior reports suggest that Native American tribal communities may have a higher prevalence of alcohol use during pregnancy; however, systematic examination using ethanol biomarkers is lacking.

METHODS

This study utilized data collected through the Navajo Birth Cohort Study (NBCS)-a birth cohort study of a Southwestern tribal community. Prevalence of prenatal alcohol exposure (PAE) was assessed by a battery of meconium biomarkers among 333 NBCS participants. Meconium samples were analyzed for nine individual fatty acid ethyl ester (FAEE) species, ethyl glucuronide (EtG), and ethyl sulfate (EtS) by LC-MS/MS.

RESULTS

Participants were recruited from five hospitals at the Navajo Nation located in Arizona (Chinle, Tséhootsooí, Tuba City) and New Mexico (Gallup, Shiprock). All participants identified as Native American; most reported a personal income of <$20,000 per year (71.3%), and ≤high school education (55.3%). The most prevalent biomarker was EtS (7.8%) followed by ethyl oleate (6.9%); 5.4% of the sample were positive for at least two biomarkers.

CONCLUSIONS

Results of this study on the prevalence of PAE in the Navajo Nation, obtained for the first time with an objective comprehensive panel of meconium biomarkers, indicate that the rates in the NBCS may be comparable to the general U.S. population and are in accord with recent U.S. national survey estimates. Our findings emphasize that drinking behaviors among Native American communities in the United States can vary, and generalization across all Native American populations is not warranted.

Assessing prevalence of alcohol consumption in early pregnancy: Self-report compared to blood biomarker analysis

Providing appropriate antenatal and postnatal care for women who drink alcohol in pregnancy is only possible if those at risk can be identified. We aimed to compare the prevalence of alcohol consumption in the first trimester of pregnancy using self-report and blood biomarker analysis. Six-hundred routine blood samples from 2014, taken at the antenatal booking appointment, in the first trimester of pregnancy, were anonymously analysed for the presence of Carbohydrate Deficient Transferrin (CDT), a validated marker of chronic alcohol exposure (normalising 2-3 weeks from abstinence) and Gamma-glutamyltransferase (GGT), a liver enzyme elevated for up to 8 weeks after alcohol exposure. In a separate sample of women, from 2015, data taken during the antenatal visit, documenting women's self-reported alcohol consumption, were collected. The percentage of women who reported alcohol intake in the first trimester was 0.8%. This compared to 74.1% of women who reported consuming alcohol before pregnancy. CDT analysis revealed a prevalence rate of 1.4% and GGT a prevalence rate of 3.5% in the first trimester of pregnancy. Although those with elevated CDT generally had high levels of GGT, only one person was positive for CDT and GGT. Results from CDT analysis and self-report may underestimate prevalence for different reasons. GGT appeared to lack specificity, but it may have value in supporting findings from CDT analysis. Further studies using additional blood biomarkers, or a combination of blood biomarkers and self-report, may be beneficial in accurately detecting alcohol drinking history in pregnancy.

Fetal Cerebral Circulation as Target of Maternal Alcohol Consumption

Alcohol (ethanol [EtOH]) is one of the most widely used psychoactive substances worldwide. Alcohol consumption during pregnancy may result in a wide range of morphological and neurodevelopmental abnormalities termed fetal alcohol spectrum disorders (FASD), with the most severe cases diagnosed as fetal alcohol syndrome (FAS). FAS and FASD are not readily curable and currently represent the leading preventable causes of birth defect and neurodevelopmental delay in the United States. The etiology of FAS/FASD remains poorly understood. This review focuses on the effects of prenatal alcohol exposure (PAE) on fetal cerebrovascular function. A brief introduction to the epidemiology of alcohol consumption and the developmental characteristics of fetal cerebral circulation is followed by several sections that discuss current evidence documenting alcohol-driven alterations of fetal cerebral blood flow, artery function, and microvessel networks. The material offers mechanistic insights at the vascular level itself into the pathophysiology of PAE.

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.

Challenges of diagnosing fetal alcohol spectrum disorders in foster and adopted children

Fetal Alcohol Spectrum Disorders (FASD) might be 10-15 times more prevalent among foster/adopted children compared to the general population; however, many of these children remain undiagnosed or misdiagnosed. The lack of confirmed prenatal alcohol exposure (PAE) may be a key barrier to diagnosis. Our sample included 681 patients evaluated for FASD, according to the University of Washington 4-Digit Diagnostic Code, at a pediatric specialty clinic. Guardianship status and other patient characteristics were evaluated by multinomial logistic regression as potential predictors of being classified into one of the following FASD groups: 1) full or partial Fetal Alcohol Syndrome (FAS/pFAS; n = 97); 2) Static Encephalopathy/Alcohol-Exposed (SE/AE) or Neurobehavioral Disorder/Alcohol-Exposed (ND/AE) (n = 135); and 3) some features of FASD (equivalent to pFAS, SE/AE or ND/AE phenotypes) but unknown PAE (n = 449). Median age at assessment was 7.0 years, non-Hispanic White constituted the predominant racial/ethnic group (49.5%), and the majority (81.8%) lacked involvement from a biological parent/relative. Many patients (66.0%) had some features of FASD but lacked reliable PAE information. Children classified into the 'some features/unknown PAE' group had higher median age of assessment (8 years) compared to other groups (6 years; p < 0.001). No association was observed between race/ethnicity or child's sex and FASD outcomes (p > 0.05). Adopted/foster children were 2.8 times as likely (95% CI: 1.6; 4.8) to be classified into the 'some features/unknown PAE' group compared to children living with a parent/relative after adjusting for covariates. This study's findings indicate that adopted/foster children are more likely to have unknown PAE and not receive a FASD diagnosis, potentially denying them access to specialized services, treatment, and rehabilitation.

Maternal hair testing to disclose self-misreporting in drinking and smoking behavior during pregnancy

This study aimed to objectively verify smoking and drinking behavior during pregnancy and to disclose self-misreporting through maternal hair analysis. A total of 153 women attending a university hospital in Barcelona (Spain) were selected and interviewed after delivery, on their smoking and drinking habits during pregnancy. A 9-cm hair strand was collected and analyzed by liquid chromatography tandem mass spectrometry for the presence of nicotine (NIC) and ethyl glucuronide (EtG) as biomarkers of tobacco and alcohol consumption, respectively. Concentrations of EtG <7 pg/mg hair and ≥30 pg/mg hair in the 0-3-cm hair segment have been used to assess, respectively, total abstinence and chronic excessive consumption in the previous 3 months, with repetitive moderate drinking lying in the interval 7-30 pg EtG per mg hair. Hair NIC less than 1 ng/mg hair indicates non-exposure to tobacco smoke while hair NIC indicates daily active smoking. In the interview, 28.1% of women declared to have smoked occasionally during gestation, while only 2.6% stated to have consumed alcohol on more than one occasion during pregnancy. Hair testing of smoking biomarkers disclosed that 7.2% of women remained active smokers during the whole pregnancy (hair NIC: 3.21-56.98 ng/mg hair), 16.3% were passive non-smokers or occasional smokers (hair NIC: 1.04-2.99 ng/mg hair), while 76.5% were not exposed to any cigarette smoke (hair NIC < limit of quantification - 0.91 ng/mg hair). Conversely, alcohol hair biomarkers showed that only 35.3% of women were totally abstinent during gestation (hair EtG: 3.89-6.73 pg/mg hair), while 62.7% drank a non-negligible amount of alcohol during pregnancy (hair EtG: 7.06-26.57 pg/mg hair), and 2% were chronic excessive drinkers (hair EtG: 35.33-47.52 pg/mg hair). Maternal hair analysis has shown to be significantly more sensitive than interviews in revealing an alarming misreported prevalence of alcohol use during pregnancy. These findings stress the need to use objective measures to assess alcohol exposure and to consider the inclusion of targeted actions to reduce alcohol consumption in maternal-child health policies.

The Ascidian Embryo Teratogenicity assay in Ciona intestinalis as a new teratological screening to test the mixture effect of the co-exposure to ethanol and fluconazole

The aim of this work was to evaluate the Ascidian Embryo Teratogenicity assay (AET) as new alternative invertebrate model to test the developmental effects of the co-exposure to ethanol and fluconazole. Ciona intestinalis embryos were exposed to the azolic fungicide fluconazole, (FLUCO, 7.8-250μM), to ethanol (Eth, 0.01-0.5%) and to their mixture (0.01% Eth+FLUCO 7.8-250μM) from neurula to larval stage. At the end of the exposure period, larvae were morphologically evaluated and benchmark analysis performed by using the PROAST modelling software. Both compounds were teratogenic in a concentration-related manner, particularly affecting the pigmented organs. The co-exposure to Eth enhanced the effects of FLUCO, the additive hypothesis was not rejected by the modelling. The results demonstrated that AET could be considered a good vertebrate-free alternative model for toxicological investigation in embryos.

Prevalence of prenatal exposure to substances of abuse: questionnaire versus biomarkers

Alcohol and drugs of abuse consumption in young adults, including women of childbearing age, has experienced significant increase over the past two decades. The use of questionnaires as the only measure to investigate prenatal alcohol and drugs of abuse exposure underestimates the real prevalence of exposure and could mislead to wrong conclusions. Therefore, the aim of this article was to compare reported rates of prenatal alcohol and drugs of abuse consumption with biomarkers of exposure by a comprehensive review of the available literature. We searched MEDLINE and EMBASE databases for articles catalogued between 1992 and 2015. We identified relevant published studies that assessed the comparison between prenatal exposure to alcohol and drugs of abuse assessed by self-reported questionnaire of consumption versus biomarkers of exposure. Thirteen studies were included regarding alcohol consumption, and seven of them about drugs of abuse. Women who admitted consumption during pregnancy by questionnaire varied from 0 to 37% for alcohol, from 0 to 4.3% for cocaine, and 2.9% for tetrahydrocannabinol (THC). Positive biomarkers results ranged from 16 to 44% for alcohol, 15.4% for cocaine, and from 4 to 12.4% for THC. Biomarkers should always complement questionnaires, as it has been shown that self-report may underestimate prenatal exposure to substances of abuse.

Placental Proteomics Reveal Insights into Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal alcohol spectrum disorders (FASD) describe many of the well-known neurodevelopmental deficits afflicting children exposed to alcohol in utero. The effects of alcohol on the maternal-fetal interface, especially the placenta, have been less explored. We herein hypothesized that chronic binge alcohol exposure during pregnancy significantly alters the placental protein profile in a rat FASD model.

METHODS

Pregnant rats were orogastrically treated daily with alcohol (4.5 g/kg, gestational day [GD] 5 to 10; 6.0 g/kg, GD 11 to 19) or 50% maltose dextrin (isocalorically matched pair-fed controls). On GD 20, placentae were collected, flash-frozen, and stored until tissues were homogenized. Protein lysates were denatured, reduced, captured on a 10-kDa spin filter, and digested. Peptides were eluted, reconstituted, and analyzed by a Q Exactive™ Hybrid Quadrupole-Orbitrap™ mass spectrometer.

RESULTS

Mass spectrometry (MS) analysis identified 2,285 placental proteins based on normalized spectral counts and 2,000 proteins by intensity-based absolute quantification. Forty-five placental proteins were significantly (p < 0.05) altered by gestational alcohol exposure by both quantification approaches. These included proteins directly related to alcohol metabolism; specific isoforms of alcohol dehydrogenase and aldehyde dehydrogenase were up-regulated in the alcohol group. Ingenuity analysis identified ethanol degradation as the most significantly altered canonical pathway in placenta, and fetal/organ development as most altered function, with increased risk for metabolic, neurological, and cardiovascular diseases. Physiological roles of the significantly altered proteins were related to early pregnancy adaptations, implantation, gestational diseases, fetal organ development, neurodevelopment, and immune functions.

CONCLUSIONS

We conclude that the placenta is a valuable organ not only to understand FASD etiology but it may also serve as a diagnostic tool to identify novel biomarkers for detecting the outcome of fetal alcohol exposure. Placental MS analysis can offer sophisticated insights into identifying alcohol metabolism-related enzymes and regulators of fetal development.

A modified Timeline Followback assessment to capture alcohol exposure in pregnant women: Application in the Safe Passage Study

Prenatal alcohol exposure (PAE) has been linked to poor pregnancy outcomes, yet there is no recognized standard for PAE assessment, and the specific effects of quantity, frequency, and timing remain largely unknown. The Safe Passage Study was designed to investigate the role of PAE in a continuum of poor peri- and postnatal outcomes. The objective of this manuscript is to describe the rationale for, and feasibility of, modifications to the traditional Timeline Followback (TLFB) for collecting PAE information in a large cohort of pregnant women. Participants from the Northern Plains region (in the United States) and Cape Town, South Africa, were followed prospectively using a modified 30-day TLFB interview, administered up to five times, to obtain detailed PAE information. Required modifications for our population included capturing information regarding sharing, type/brand, container size, and duration, in order to accurately record the amount of alcohol consumed. PAE status was defined for 99.9% of the 11,892 enrolled pregnancies at least once during pregnancy and for 92% across all trimesters. Of 53,823 drinks reported, 98% had all items necessary for standard drink computation. Sharing was reported for 74% of drinks in Cape Town, South Africa and for 10% in the Northern Plains. Compared to referent values from the traditional TLFB, 74% and 67% of drinks had different alcohol-by-volume and container size, respectively. Furthermore, a statistically significant difference was found between the number of containers reported and the number of standard drinks computed, using information from the modified TLFB. This is the first study of this size to wholly encompass all of these changes into a single measure in order to more accurately calculate daily consumption and assess patterns over time. The methods used to collect PAE information and create alcohol exposure measures likely increased the accuracy of standard drinks reported and could be generalized to other populations.

Drinking and smoking patterns during pregnancy: Development of group-based trajectories in the Safe Passage Study

Precise identification of drinking and smoking patterns during pregnancy is crucial to better understand the risk to the fetus. The purpose of this manuscript is to describe the methodological approach used to define prenatal drinking and smoking trajectories from a large prospective pregnancy cohort, and to describe maternal characteristics associated with different exposure patterns. In the Safe Passage Study, detailed information regarding quantity, frequency, and timing of exposure was self-reported up to four times during pregnancy and at 1 month post-delivery. Exposure trajectories were developed using data from 11,692 pregnancies (9912 women) where pregnancy outcome was known. Women were from three diverse populations: white (23%) and American Indian (17%) in the Northern Plains, US, and mixed ancestry (59%) in South Africa (other/not specified [1%]). Group-based trajectory modeling was used to identify 5 unique drinking trajectories (1 none/minimal, 2 quitting groups, 2 continuous groups) and 7 smoking trajectories (1 none/minimal, 2 quitting groups, 4 continuous groups). Women with pregnancies assigned to the low- or high-continuous drinking groups were less likely to have completed high school and were more likely to have enrolled in the study in the third trimester, be of mixed ancestry, or be depressed than those assigned to the none/minimal or quit-drinking groups. Results were similar when comparing continuous smokers to none/minimal and quit-smoking groups. Further, women classified as high- or low-continuous drinkers were more likely to smoke at moderate-, high-, and very high-continuous levels, as compared to women classified as non-drinkers and quitters. This is the first study of this size to utilize group-based trajectory modeling to identify unique prenatal drinking and smoking trajectories. These trajectories will be used in future analyses to determine which specific exposure patterns subsequently manifest as poor peri- and postnatal outcomes.

Metabolomics and fetal alcohol spectrum disorder

Fetal alcohol spectrum disorder (FASD) is a major public health issue that encompass an array of physical, neurological, and behavioral effects due to alcohol consumption during pregnancy. The classical biomarkers of FASD that are currently used lack sensitivity and specificity, and as such there is an opportunity through the use of novel metabolomics analysis to identify new biomarkers to identify those at risk for FASD, which could more effectively aid in early intervention. The focus of this minireview is to identify current work that is being done in the field of metabolomics in FASD in utero, and to highlight promising metabolites that could act as biomarkers in the future. We will conclude with suggestions for further research, as there is a large gap of knowledge in this particular area of metabolomics.

Ethyl linolenate is elevated in meconium of very-low-birth-weight neonates exposed to alcohol in utero

BACKGROUND

The health implications of in utero alcohol exposure have been difficult to study in very-low-birth-weight newborns (VLBW) because of an inability to identify maternal alcohol exposure. Fatty acid ethyl esters (FAEEs) are elevated in meconium of alcohol-exposed term newborns. We hypothesized that meconium FAEEs would be similarly elevated in alcohol-exposed VLBW premature newborns.

METHODS

In a retrospective cohort study of 64 VLBW neonates, newborns were classified into Non-Exposed, Any Exposure, or Weekly Exposure groups based on an in-depth structured maternal interview. Meconium FAEE concentrations were quantified via gas chromatography mass spectrometry.

RESULTS

Alcohol exposure during Trimester 1 (Any Exposure) occurred in ~30% of the pregnancies, while 11% of the subjects reported drinking ≥ 1 drink/week (Weekly Exposure). Meconium ethyl linolenate was higher in Any Exposure (P = 0.01) and Weekly Exposure groups (P = 0.005) compared to the Non-Exposed VLBW group. There was a significant positive correlation between Trimester 1 drinking amounts and the concentration of meconium ethyl linolenate (P = 0.005). Adjusted receiver operating characteristic (ROC) curves evaluating ethyl linolenate to identify alcohol-exposed VLBW newborns generated areas under the curve of 88% with sensitivities of 86-89% and specificities of 83-88%.

CONCLUSION

Despite prematurity, meconium FAEEs hold promise to identify the alcohol-exposed VLBW newborn.

Biomarkers for the Detection of Prenatal Alcohol Exposure: A Review

Alcohol exposure during pregnancy can cause adverse effects to the fetus, because it interferes with fetal development, leading to later physical and mental impairment. The most common clinical tool to determine fetal alcohol exposure is maternal self-reporting. However, a more objective and useful method is based on the use of biomarkers in biological specimens alone or in combination with maternal self-reporting. This review reports on clinically relevant biomarkers for detection of prenatal alcohol exposure (PAE). A systematic search was performed to ensure a proper overview in existing literature. Studies were selected to give an overview on clinically relevant neonatal and maternal biomarkers. The direct biomarkers fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG), ethyl sulfate, and phosphatidylethanol (PEth) were found to be the most appropriate biomarkers in relation to detection of PAE. To review each biomarker in a clinical context, we have compared the advantages and disadvantages of each biomarker, in relation to its window of detectability, ease of collection, and the ease and cost of analysis of each biomarker. The biomarkers PEth, FAEEs, and EtG were found to be applicable for detection of even low levels of alcohol exposure. Meconium is an accessible matrix for determination of FAEEs and EtG, and blood an accessible matrix for determination of PEth.

In utero alcohol effects on foetal, neonatal and childhood lung disease

Maternal alcohol use during pregnancy exposes both premature and term newborns to the toxicity of alcohol and its metabolites. Foetal alcohol exposure adversely effects the lung. In contrast to the adult "alcoholic lung" phenotype, an inability to identify the newborn exposed to alcohol in utero has limited our understanding of its effect on adverse pulmonary outcomes. This paper will review advances in biomarker development of in utero alcohol exposure. We will highlight the current understanding of in utero alcohol's toxicity to the developing lung and immune defense. Finally, we will present recent clinical evidence describing foetal alcohol's association with adverse pulmonary outcomes including bronchopulmonary dysplasia, viral infections such as respiratory syncytial virus and allergic asthma/atopy. With research to define alcohol's effect on the lung and translational studies accurately identifying the exposed offspring, the full extent of alcohol's effects on clinical respiratory outcomes of the newborn or child can be determined.

Assays of Gamma-Glutamyl Transferase and Carbohydrate-Deficient Transferrin Combination from Maternal Serum Improve the Detection of Prenatal Alcohol Exposure

BACKGROUND

Alcohol use during pregnancy leads to detrimental effects on fetal development. As self-reports by mothers are known to be unreliable for assessing prenatal alcohol exposure, there is a need for sensitive and specific biomarkers for identifying those at risk for alcohol-affected offspring.

METHODS

We measured serum gamma-glutamyl transferase (GGT), carbohydrate-deficient transferrin (CDT), a mathematically formulated combination of GGT and CDT (GGT-CDT), and ethylglucuronide (EtG) concentrations from 1,936 mothers with a positive (n = 480) or negative (n = 1,456) history of alcohol use at the time of pregnancy. The material included 385 alcohol-abusing mothers who subsequently gave birth to children with fetal alcohol syndrome (FAS) and 1,551 mothers without FAS children including 95 women who reported a median of 1.0 standard drinks of alcohol per day during pregnancy and 1,456 nondrinking controls. Among those without FAS outcome, there were 405 mothers with gestational diabetes mellitus (GDM) and 745 mothers representing lifelong abstainers.

RESULTS

Mothers of FAS children had higher mean GGT, CDT, GGT-CDT, and EtG levels than abstainers (p < 0.001 for all comparisons) or mothers reporting some alcohol consumption but whose children were not diagnosed with FAS (p < 0.001 for all comparisons). In receiver operating characteristic analyses using cutoffs based on abstainers, the area under the curves (AUCs) for GGT-CDT (0.873) were higher than those of GGT (0.824), CDT (0.776), or EtG (0.584) for differentiating the mothers of FAS children and abstainers. Unlike CDT, this combination marker also differed significantly between drinking mothers without FAS outcome and abstainers (AUC = 0.730, p < 0.001). In comparisons adjusted for GDM and body mass index, the group of mothers who had reported a median of 1.0 standard drinks of alcohol per day during pregnancy also differed from the group reporting no current alcohol intake in GGT (p < 0.02) and GGT-CDT (p < 0.01) levels.

CONCLUSIONS

Combination of GGT and CDT improves the identification of prenatal alcohol exposure and associated high-risk pregnancies. A more systematic use of biomarkers may help intervention efforts to prevent alcohol-induced adverse effects on fetal development.

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.

Fetal alcohol spectrum disorders: Prevention, identification, and intervention

Fetal alcohol spectrum disorders (FASD) remain a common cause of intellectual disability in infants and children, with an estimated incidence of 9.1 out of every 1,000 U.S. live births. This article discusses methods for identifying and assisting women who consume alcohol prenatally and referring infants and children with FASD for intervention.

Alternative sampling strategies for the assessment of alcohol intake of living persons

Monitoring of alcohol consumption by living persons takes place in various contexts, amongst which workplace drug testing, driving under the influence of alcohol, driving licence regranting programs, alcohol withdrawal treatment, diagnosis of acute intoxication or fetal alcohol ingestion. The matrices that are mostly used today include blood, breath and urine. The aim of this review is to present alternative sampling strategies that allow monitoring of the alcohol consumption in living subjects. Ethanol itself, indirect (carbohydrate deficient transferrin, CDT%) as well as direct biomarkers (ethyl glucuronide, EtG; ethyl sulphate, EtS; fatty acid ethyl esters, FAEEs and phosphatidylethanol species, PEths) of ethanol consumption will be considered. This review covers dried blood spots (CDT%, EtG/EtS, PEths), dried urine spots (EtG/EtS), sweat and skin surface lipids (ethanol, EtG, FAEEs), oral fluid (ethanol, EtG), exhaled breath (PEths), hair (EtG, FAEEs), nail (EtG), meconium (EtG/EtS, FAEEs), umbilical cord and placenta (EtG/EtS and PEth 16:0/18:1). Main results, issues and considerations specific to each matrix are reported. Details about sample preparation and analytical methods are not within the scope of this review.

Alcohol Consumption during Pregnancy: Analysis of Two Direct Metabolites of Ethanol in Meconium

Alcohol consumption in young women is a widespread habit that may continue during pregnancy and induce alterations in the fetus. We aimed to characterize prevalence of alcohol consumption in parturient women and to assess fetal ethanol exposure in their newborns by analyzing two direct metabolites of ethanol in meconium. This is a cross-sectional study performed in September 2011 and March 2012 in a series of women admitted to an obstetric unit following childbirth. During admission, socio-demographic and substance use (alcohol, tobacco, cannabis, cocaine, and opiates) during pregnancy were assessed using a structured questionnaire and clinical charts. We also recorded the characteristics of pregnancy, childbirth, and neonates. The meconium analysis was performed by liquid chromatography—tandem mass spectrometry (LC-MS/MS) to detect the presence of ethyl glucuronide (EtG) and ethyl sulfate (EtS). Fifty-one parturient and 52 neonates were included and 48 meconium samples were suitable for EtG and EtS detection. The median age of women was 30 years (interquartile range (IQR): 26–34 years); EtG was present in all meconium samples and median concentration of EtG was 67.9 ng/g (IQR: 36.0–110.6 ng/g). With respect to EtS, it was undetectable (<0.01 ng/g) in the majority of samples (79.1%). Only three (6%) women reported alcohol consumption during pregnancy in face-to-face interviews. However, prevalence of fetal exposure to alcohol through the detection of EtG and EtS was 4.2% and 16.7%, respectively. Prevention of alcohol consumption during pregnancy and the detection of substance use with markers of fetal exposure are essential components of maternal and child health.