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

Prenatal exposure to alcohol and its impact on reward processing and substance use in adulthood

Heavy maternal alcohol drinking during pregnancy has been associated with altered neurodevelopment in the child but the effects of low-dose alcohol drinking are less clear and any potential safe level of alcohol use during pregnancy is not known. We evaluated the effects of prenatal alcohol on reward-related behavior and substance use in young adulthood and the potential sex differences therein. Participants were members of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) prenatal birth cohort who participated in its neuroimaging follow-up in young adulthood. A total of 191 participants (28-30 years; 51% men) had complete data on prenatal exposure to alcohol, current substance use, and fMRI data from young adulthood. Maternal alcohol drinking was assessed during mid-pregnancy and pre-conception. Brain response to reward anticipation and reward feedback was measured using the Monetary Incentive Delay task and substance use in young adulthood was assessed using a self-report questionnaire. We showed that even a moderate exposure to alcohol in mid-pregnancy but not pre-conception was associated with robust effects on brain response to reward feedback (six frontal, one parietal, one temporal, and one occipital cluster) and with greater cannabis use in both men and women 30 years later. Moreover, mid-pregnancy but not pre-conception exposure to alcohol was associated with greater cannabis use in young adulthood and these effects were independent of maternal education and maternal depression during pregnancy. Further, the extent of cannabis use in the late 20 s was predicted by the brain response to reward feedback in three out of the nine prenatal alcohol-related clusters and these effects were independent of current alcohol use. Sex differences in the brain response to reward outcome emerged only during the no loss vs. loss contrast. Young adult men exposed to alcohol prenatally had significantly larger brain response to no loss vs. loss in the putamen and occipital region than women exposed to prenatal alcohol. Therefore, we conclude that even moderate exposure to alcohol prenatally has long-lasting effects on brain function during reward processing and risk of cannabis use in young adulthood.

Defining trimester-specific reference intervals for carbohydrate deficient transferrin in pregnant women

OBJECTIVES

Extensive consumption of alcohol during pregnancy can lead to severe complications for the unborn child. Carbohydrate-deficient transferrin (CDT) levels in serum have become a common biomarker for excessive alcohol intake. However, during pregnancy CDT levels can rise to levels above commonly used cut-off values, for reasons unrelated to alcohol intake. The aim of this study is to investigate the changes in CDT values during pregnancy and to determine accurate, trimester dependent reference intervals.

METHODS

439 serum samples of 147 healthy pregnant women were obtained for trimester 1, 2, 3, and post-partum and were analysed by high-performance liquid chromatography (HPLC) and an N-Latex immunonephelometric assay. New trimester-specific reference intervals were established.

RESULTS

This study demonstrates there is a trimester-dependent increase of %CDT, as up to 39.4% of the population exceeded the previously established upper reference limit of 1.7%. In our study the estimated upper reference limit for %DST/%CDT were 1.55%, 1.96%, 2.05% and 1.35% for trimester 1, 2, 3 and post-partum for the HPLC-method and 2.02%, 2.19%, 2.19% and 1.96% for the N-Latex immunoassay.

CONCLUSIONS

We demonstrate that CDT levels rise during pregnancy. The magnitude of the increase is method-dependent and needs to be taken into account. We have established method- and trimester-specific reference intervals to prevent false-positive results in alcohol abuse screening tests during pregnancy.

Identifying Prenatal Alcohol Exposure and Children Affected by It: A Review of Biomarkers and Screening Tools

PURPOSE

Early identification of prenatal alcohol exposure (PAE) and of those in need of services resulting from this exposure is an important public health concern. This study reviewed the existing literature on potential biomarkers and screening tools of PAE and its impact.

SEARCH METHODS

Electronic databases were searched for articles published between January 1, 1996, and November 30, 2021, using the following search terms: ("fetal alcohol" or "prenatal alcohol" or "FASD" or "alcohol-related neurodevelopmental disorder" or "ARND" or "ND-PAE") and ("screening" or "identification" or "biomarker"). Duplicate articles were electronically eliminated. Titles and abstracts were reviewed for appropriateness, and selected articles were retrieved for further analysis. Additional articles were added that were referenced in the reviewed articles or identified from expert knowledge. Information about the characteristics of the sample, the biomarker or screening tool, and the predictive validity outcome data were abstracted. A narrative analysis of the studies was then performed on the data.

SEARCH RESULTS

A total of 3,813 articles were initially identified, and 1,215 were removed as duplicates. Of the remaining articles, 182 were identified as being within the scope of the review based on title and abstract inspection, and 181 articles were successfully retrieved. Of these, additional articles were removed because they were preclinical (3), were descriptive only (13), included only self-report of PAE (42), included only mean group comparison (17), were additional duplicates (2), focused on cost analysis (9), missed predictive validity data (24), or for other reasons (23). The remaining articles (n = 48) were abstracted. An additional 13 manuscripts were identified from these articles, and two more from expert knowledge. A total of 63 articles contributed to the review.

DISCUSSION AND CONCLUSIONS

Biomarkers and screening tools of PAE and its impact fall short of ideal predictive validity characteristics. Higher specificity than sensitivity was found for many of the biomarkers and screening tools used to identify PAE and its impact, suggesting that current methods continue to under-identify the full range of individuals impacted by PAE. Exceptions to this were found in recent investigations using microRNAs related to growth and vascular development, proteomic changes associated with PAE, and combinations of markers estimating levels of various cytokines. Replications of these findings are needed across other samples to confirm the limited data available. Future research on biomarkers and screening tools should attend to feasibility and scalability of implementation. This article also recommends a systematic process of evaluation to improve early identification of individuals impacted by PAE so that harm reduction and habilitative care efforts can be implemented.

Validation of serotonin transporter mRNA as a quantitative biomarker of heavy drinking and its comparison to ethyl glucuronide/ethyl sulfate: A randomized, double-blind, crossover trial

BACKGROUND

The serotonin transporter (SERT) mRNA was previously reported to be a quantitative and pathophysiology-based biomarker of heavy drinking in 5HTTLPR:LL genotype-carriers treated with ondansetron. Here, we validated the potential use of SERT mRNA for quantitative prediction of recent alcohol consumption (in the absence of treatment) and compared it with the known biomarkers ethyl glucuronide (EtG) and ethyl sulfate (EtS).

METHODS

Binge drinking men and women of European ancestry aged 21 to 65 years were enrolled in a 12-day, in-patient, randomized, double-blind, crossover study, where they were administered three beverage doses (placebo, 0.5 g/kg [0.4 g/kg] ethanol, and 1 g/kg [0.9 g/kg] ethanol for men [women]) individually in three 4-day periods (experiments), separated by minimum 7-day washout period. Diet, sleep, and physical activity were controlled throughout the inpatient experiments. Twenty-nine participants were randomized to receive beverage doses counterbalancing the sequence of treatment and gender within subgroups stratified by SERT genotypes 5HTTLPR:LL+rs25531:AA (LA LA ) versus 5HTTLPR:LS/SS. Peripheral venous blood was collected daily for (1) quantification of SERT mRNA (the primary outcome measure) using qRT-PCR and (2) plasma EtG and EtS levels using tandem mass-spectrometry.

RESULTS

The association between administered beverage dose and SERT mRNA from completers of at least one 4-day experiment (N = 18) assessed by a linear mixed model was not statistically significant. Significant positive associations were found with beverage dose and plasma EtG, EtS and EtG/EtS ratio (β = 5.8, SE = 1.2, p < 0.0001; β = 1.3, SE = 0.6, p = 0.023; and β = 3.0, SE = 0.7, p < 0.0001, respectively; the C-statistics for discriminating outcomes were 0.97, 0.8, and 0.92, respectively). Additionally, we observed a sequence effect with a greater placebo effect on SERT mRNA when it was administered during the first experiment (p = 0.0009), but not on EtG/EtS measures.

CONCLUSION

The findings do not validate the use of SERT as a biomarker of heavy drinking. Larger and more innovative studies addressing the effects of placebo, race, gender, and response to treatment with serotonergic agents are needed to fully assess the utility of SERT as a biomarker of heavy and binge drinking.

Can routine screening for alcohol consumption in pregnancy be ethically and legally justified?

In the UK, it has been proposed that alongside the current advice to abstain from alcohol completely in pregnancy, there should be increased screening of pregnant women for alcohol consumption in order to prevent instances of fetal alcohol spectrum disorder. The Scottish Intercollegiate Guidelines Network published guidelines in 2019 recommending that standardised screening questionnaires and associated use of biomarkers should be considered to identify alcohol exposure in pregnancy. This was followed in 2020 by the National Institute for Health and Care Excellence Draft Quality Standard, which recommended that pregnant women should have information on their alcohol consumption recorded throughout their pregnancy and this information transferred to the child's health records. Most recently, Public Health England has stated that the alcohol intake of all women should be recorded throughout pregnancy, not just at the initial booking appointment and that tools such as blood biomarkers and meconium testing should be researched in order to determine true prevalence rates of alcohol in pregnancy. We argue that this proposed enhanced screening undermines women's autonomy and their legal right to be sufficiently informed to consent to screening. We argue that there is no evidence that this kind of screening will result in a reduction of fetal harm and there is a danger that undermining the autonomy of women and the trust relationship between women and healthcare professionals may even increase harm to future children.

Abnormal growth and morphogenesis of placenta at term is linked to adverse fetal development after perigestational alcohol consumption up to early gestation in mouse

BACKGROUND

Gestation alcohol consumption produces fetal growth restriction and malformations by affecting the embryo-fetal development. Recently a relationship between abnormal placentation and fetal malformation and intrauterine growth retardation has been suggested. However, the effects of perigestational alcohol ingestion up to early pregnancy on the placenta at term and its association with fetal abnormalities are little known.

METHODS

In female mice, ethanol 10% in water was administered for 15 days previous and up to days 4 (D4), 8 (D8), or 10 (D10) of gestation (TF), and gestation continues without ethanol exposure. Control females (CF) received ethanol-free water. At day 18, feto-placental units and implantation sites were studied.

RESULTS

TF had increased resorptions and only fetuses from D8-TF and D10-TF had significantly increased weights versus CF. D4 and D10-TF-placentas had significantly reduced weights. All TF had increased junctional zone (JZ) and reduced labyrinth (Lab) areas (PAS-histology and morphometry) compared with CF. Fetuses with mainly with craniofacial abnormalities and skeletal defects (Alizarin red staining), significantly increase; while the fetal bone density (alizarin color intensity, ImageJ) was reduced in D4, D8 and D10-TF versus CF. Although all TF-placentas were histo-structural affected, TF-abnormal fetuses had the most severe placental anomalies, with junctional abundant glycogenic cells into the labyrinth, disorganized labyrinthine vascularization with signs of leukocyte infiltrates and feto-maternal blood mix.

CONCLUSIONS

Perigestational alcohol consumption up to early gestation induces at term fetal growth alterations, dysmorphology and defective skeleton, linked to deficient growth and abnormal morphogenesis of placenta, highlighting insight into the prenatal etiology of FASD.

Fetal alcohol spectrum disorders: an overview of current evidence and activities in the UK

Estimates for the UK suggest that alcohol consumption during pregnancy and prevalence of fetal alcohol spectrum disorder (FASD)-the most common neurodevelopmental condition-are high. Considering the significant health and social impacts of FASD, there is a public health imperative to prioritise prevention, interventions and support. In this article, we outline the current state of play regarding FASD knowledge and research in the UK, which is characterised by a lack of evidence, a lack of dedicated funding and services, and consequently little policy formulation and strategic direction. We highlight progress made to date, as well as current knowledge and service gaps to propose a way forward for UK research.

Perigestational alcohol consumption induces altered early placentation and organogenic embryo growth restriction by disruption of trophoblast angiogenic factors

RESEARCH QUESTION

Maternal alcohol consumption produces fetal retardation and malformations, probably associated with placental defects. Does perigestational alcohol consumption up to organogenesis lead to abnormal placentation and embryo growth restriction by disrupting the vascular endothelial growth factor (VEGF) system in embryo-placental development?

DESIGN

Female mice were treated with 10% ethanol in drinking water before and up to day 10 of gestation. Control mice received ethanol-free water. After treatment, the trophoblastic tissue, embryo growth and the angiogenic VEGF pathway were analysed.

RESULTS

Female mice who had received treatment had resorbed and delayed implantation sites with poor ectoplacental cone development. Reduced trophoblastic area tissue from female mice who had received treatment had abnormal junctional zone and diminished labyrinthine vascularization. After treatment, the labyrinth had increased chorionic trophoblast proliferation, hypoxia inducible factor-1α immunoexpression but reduced apoptosis. The embryo growth was reduced concomitantly with low VEGF immunostaining but high endothelial nitric oxide synthase (eNOS) expression. In junctional and labyrinth of treated female mice, gene and protein immunoexpression of VEGF was reduced and the protein expression of FLT-1 increased compared with controls. Increased activation of kinase insert domain receptor receptor (phosphorylated KDR) and expression of eNOS were observed in placenta of treated female mice. Immunoexpression of metalloproteinase-9, however, was reduced in junctional zone but increased in labyrinth, compared with controls.

CONCLUSIONS

These data reveal inadequate expression of VEGF/receptors and angiogenic eNOS and metalloproteinase factors related to abnormal early placentation after perigestational alcohol ingestion, providing insight into aetiological factors underlying early placentopathy associated with intrauterine growth restriction caused by maternal alcohol consumption.

An Integrative Screening Tool of Alcohol Exposure During Early Pregnancy: Combining of the CDT Biomarker with Green Page Questionnaire

AIMS

In current clinical practice, prenatal alcohol exposure is usually assessed by interviewing the pregnant woman by applying questionnaires. An alternative method for detecting alcohol use is to measure the biomarker carbohydrate-deficient transferrin (CDT). However, few studies measure CDT during pregnancy. This study examines the utility of CDT biomarker in the screening of alcohol exposure during early pregnancy.

METHODS

A cohort of 91, first-trimester pregnant women assigned to a public reference maternity hospital, was screened using the Green Page (GP) questionnaire, an environmental exposure tool. CDT levels and other biomarkers of alcohol use were measured and compared with questionnaire data.

RESULTS

About 70% of the mothers in the study consumed alcohol during early pregnancy and 22% met high-risk criteria for prenatal exposure to alcohol. CDT measurement showed a statistically significant area under the receiver operating characteristic curve with a value of 0.70. For a value of 0.95% of CDT, a specificity of 93% was observed. The most significant predictors of CDT were the number of binge drinking episodes, women's body mass index and European white race.

CONCLUSION

Pregnant women with a CDT value >0.95% would be good candidates for the performance of the GP questionnaire during early pregnancy in order to detect potential high-risk pregnancy due to alcohol exposure.

CDT reference values for monitoring chronic alcohol abuse in pregnancy

INTRODUCTION AND AIM

Carbohydrate Deficient Transferrin (CDT) is one of the most used biomarkers for monitoring alcohol use in pregnancy. However, its effective application in this context is hampered by the demonstrated physiological progressive increase during pregnancy (even in abstinent women) of CDT values, which in the third trimester can reach values close or exceeding the cut-offs usually adopted in clinical and forensic diagnostics. The present work was aimed at the re-assessment of CDT reference values in pregnancy.

MATERIALS AND METHODS

The CDT analysis was performed by a validated HPLC-UV Vis method on 284 serum samples of women with a physiological pregnancy and on 370 sera of non-pregnant woman from the general population (control group). All the samples were tested also for GGT for excluding alcohol abuse. The statistical analysis was performed using the MedCalc® Statistical Software.

RESULTS

The re-definition of the specific reference concentrations was carried out according to the Horn and Pesce Robust Method. The resulting CDT upper reference values were 1.45%, 2.01% and 2.05% in the first, second, and third trimester, respectively.

CONCLUSIONS

In order to prevent the development of maternal and fetal prenatal alcohol exposure complications, the use of alcohol biomarkers, including CDT, has been proposed. However, this biomarker, in the monitoring of alcohol use in pregnancy, has so far been applied adopting the same cut-off used for general population without taking into consideration the progressive physiological increase of its value throughout the pregnancy. In the present study, a specific re-assessment of the CDT reference concentrations of each trimester is reported.

Pregnant Women's Risk Perception of the Teratogenic Effects of Alcohol Consumption in Pregnancy

There is ample evidence of the teratogenic effects of prenatal alcohol exposure, with long-term consequences throughout the entire life cycle. Nevertheless, research on risk perception of alcohol consumption among pregnant women is scarce. In order to analyze risk perception of alcohol consumption during pregnancy, a cross-sectional study was conducted with a random sample of 426 pregnant women (in their 20th week of gestation) receiving care at the outpatient clinics of a public university hospital in the southern European city of Seville (Spain). Data were collected through structured face-to-face interviews conducted by trained health professionals using a customized questionnaire. Data analysis included structural equation modeling. Only 48.1% of the sample indicated that the sequelae from alcohol consumption during pregnancy were life-long. The structural equation model showed that a lower risk perception about beer and wine consumption, and a lower educational level, were related to more frequent alcohol consumption. Younger participants showed lower risk perception concerning beer consumption. Higher levels of education were related to a greater risk perception of beer. Healthcare institutions should articulate programs that facilitate health advice regarding alcohol consumption during pregnancy, particularly when providing care for women with low educational levels.

Assessment of alcohol consumption in depression follow-up using self-reports and blood measures including inflammatory biomarkers

AIMS

Alcohol consumption has been suggested a major role in the pathogenesis and prognosis of depression. However, reliable identification of hazardous drinking continues to be problematic. We compared the accuracy of different biomarkers and self-reports of alcohol consumption in the follow-up study of depression.

METHODS

Data from 202 patients with major depressive disorder were obtained through self-reports, AUDIT and AUDIT-C questionnaires and biomarker analyses. The clinical assessments and measurements of biomarkers (GT, CDT, GT-CDT-combination, MCV, ALT, AST, hs-CRP, IL-6) were performed at baseline and after six months of treatment. Based on self-reported alcohol intake at baseline the patients were classified to three subgroups.

RESULTS

About 27.2% of patients were categorized to high-risk drinkers, 26.3% low-risk drinkers and 46.5% abstainers. High-risk drinkers showed significantly higher mean values of GT, CDT, GT-CDT-combination and IL-6 than abstainers, diagnostic accuracy being highest with the combined marker of GT-CDT. The accuracy of AUDIT and AUDIT-C to detect high-risk drinking was also significant. During follow-up, the differences observed in the biomarkers at baseline disappeared together with recovery from depression.

CONCLUSIONS

Our data suggest the combined use of GT-CDT and AUDIT questionnaires to improve the identification of drinking of patients with depression. This approach could be useful for improving treatment adherence and outcome in depressed patients.

Assessing the prevalence of alcohol consumption in early pregnancy using blood biomarker analysis: a consistent pattern across north-east England?

Background

We previously investigated the prevalence of alcohol consumption in early pregnancy in Northumbria Healthcare NHS Foundation Trust, a locality of north-east England. The prevalence was 1.4% based on blood sample biomarker analysis using carbohydrate deficient transferrin (CDT) and 3.5% for gamma-glutamyltransferase (GGT).

Aims

To supplement this research by investigating the prevalence of alcohol use using identical methods in a different locality of the same region.

Methods

Six-hundred random blood samples taken at the antenatal booking appointment were anonymously analysed for the presence of CDT, a validated marker of chronic alcohol exposure (normalizing 2–3 weeks from abstinence) and GGT, a liver enzyme elevated for up to 8 weeks after alcohol exposure.

Results

The North Tees and Hartlepool NHS Foundation Trust data revealed a CDT prevalence rate of 1.7% (95% CI: 0.7–2.9) and GGT prevalence rate of 4.2% (95% CI: 2.6–5.9). However, these measures are not sensitive to low levels of alcohol; and no overlapping cases were identified or a significant correlation demonstrated between CDT or GGT.

Discussion

These data support our earlier work. Prevalence rates according to CDT and GGT analysis were similar in both areas, suggesting similar patterns of sustained alcohol use in pregnancy across the region.