Objective assessment of alcohol consumption in early pregnancy using phosphatidylethanol: a cross-sectional study

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

Alcohol exposure before and during pregnancy is associated with reduced fetal growth: the Safe Passage Study

BACKGROUND

Prenatal alcohol exposure (PAE) is a worldwide public health concern. While PAE is known to be associated with low birth weight, little is known about timing and quantity of PAE on fetal growth. This study investigated the association between periconceptional and prenatal alcohol exposure and longitudinal fetal growth, focusing on timing and quantity in a high exposure cohort.

METHODS

The Safe Passage Study was a prospective cohort study, including 1698 pregnant women. Two-dimensional transabdominal ultrasound examinations were performed to measure fetal femur length, abdominal and head circumference, and biparietal diameter, at three time points during pregnancy. Estimated fetal weight and Z-scores of all parameters were calculated. Trimester-specific alcohol exposure was assessed using the Timeline Followback method. To investigate the associations of specific timing of PAE and fetal growth, two models were built. One with alcohol exposure as accumulative parameter over the course of pregnancy and one trimester specific model, in which PAE was separately analyzed. Linear mixed models adjusted for potential confounders were applied with repeated assessments of both alcohol exposure and fetal growth outcomes.

RESULTS

This study demonstrated that periconceptional and prenatal alcohol exposure were associated with reduced fetal growth. Effect sizes are displayed as estimated differences (ED) in Z-score and corresponding 95% confidence intervals (95% CIs). When investigated as accumulative parameter, PAE was related to a smaller femur length (ED30; - 0.13 (95% CI; - 0.22; - 0.04), ED36; - 0.14 (95% CI; - 0.25; - 0.04)) and a smaller abdominal circumference (ED36; - 0.09 (95% CI; - 0.18; - 0.01)). Periconceptional alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.14 (95% CI; - 0.25; - 0.02), ED36; - 0.22 (95% CI; - 0.37; - 0.06)) and a smaller estimated fetal weight (ED36; - 0.22 (95% CI; - 0.38; - 0.05)). Second trimester alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.49 (95% CI; - 0.86; - 0.12), ED36; - 0.70 (95% CI; - 1.22; - 0.17)) and estimated fetal weight (ED30; - 0.54 (95% CI; - 0.94; - 0.14), ED36; - 0.69 (95% CI; - 1.25; - 0.14)). No additional association of binge drinking was found besides the already observed association of PAE and fetal growth.

CONCLUSIONS

This study demonstrated that PAE negatively affects fetal growth, in particular when exposed during the periconception period or in second trimester. Our results indicate that potential negative consequences of PAE are detectable already before birth. Therefore, healthcare providers should actively address and discourage alcohol use during pregnancy.

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.

Can PEth be Detected with a Cutoff of 20 ng/mL after Single Alcohol Consumption?

Phosphatidylethanol (PEth) can be determined in capillary blood collected as dried blood spots (DBS) and is a promising direct alcohol biomarker for the determination of drinking habits. Its use for abstinence monitoring needs to be evaluated. Studies with patients undergoing alcohol withdrawal have shown that the elimination of PEth can take up to 2 months. For the determination of PEth 16:0/18:1, a cutoff of 20 ng/mL has been agreed upon in the major US laboratories. However, it is not yet clear what minimum blood alcohol concentrations (BACs) have to be achieved by a single drinking episode to result in PEth concentrations above this cutoff after previous long-term abstinence. To determine whether low drinking amounts can result in a positive PEth concentration above 20 ng/mL, we recruited 12 participants ('social' drinkers). After 4 weeks of abstinence, alcohol was consumed at two separate drinking events with target BACs of 0.5 and 0.3 g/kg, resulting in maximum BACs in the ranges of 0.30-0.63 g/kg and 0.10-0.28 g/kg, respectively. Capillary blood was collected at different time points of the drinking experiment, and PEth was extracted from DBS and analyzed by liquid chromatography-tandem mass spectrometry. Despite drinking doses up to 0.58 g ethanol per kg body weight and reaching BACs of up to 0.63 g/kg, PEth 16:0/18:1 and PEth 16:0/18:2 could not be detected at or above the 20 ng/mL cutoff in any participant at any time after the drinking events. We conclude that after long-term abstinence the cutoff of 20 ng/mL for single alcohol consumption leading to BACs up to 0.63 g/kg is not exceeded.

Piloting a complex intervention to promote a tobacco and alcohol-free pregnancy: the Smoke and Alcohol Free with EHealth and Rewards (SAFER) pregnancy study

BACKGROUND

Tobacco smoking and alcohol consumption before and during pregnancy increase the risk of adverse health outcomes for mother and child. Interventions to address smoking and drinking before and during pregnancy have the potential to reduce early-life health inequalities. In the Smoke and Alcohol Free with EHealth and Rewards (SAFER) pilot study we aimed to evaluate the acceptability, feasibility and effectiveness of a complex intervention supporting women in smoking and alcohol cessation before and during pregnancy.

METHODS

From February 2019 till March 2021, we piloted the SAFER pregnancy intervention among pregnant women and women planning pregnancy in South-West Netherlands in an uncontrolled before-after study. Participants were supported in smoking and alcohol cessation via up to six group sessions and an online platform. In addition, biochemically validated cessation was rewarded with incentives (i.e. shopping vouchers) amounting up to 185 euros. We aimed to include 66 women. The primary outcome was smoking and/or alcohol cessation at 34-38 weeks of gestation (if pregnant) or after six group sessions (if not pregnant). Quantitative data were analysed using descriptive statistics. Focus group interviews among those involved in the study were conducted at the end of the study to explore their experiences. Qualitative data was analysed using thematic analysis.

RESULTS

Thirty-nine women who smoked were included; no women who consumed alcohol were referred to the study. Unemployment (51%), financial problems (36%) and a smoking partner (72%) were common. Thirteen women (33%) dropped out, often due to other problems impeding smoking cessation or 'being too busy' to participate in the group sessions. Eleven women (28%) had quit smoking at the study's endpoint. The personal and positive approach was highly valued and biochemical validation was felt to be helpful.

CONCLUSION

The SAFER pregnancy intervention seems appropriate for women in need of extra support for smoking cessation before and during pregnancy. Its impact on alcohol cessation could not be studied due to recruitment issues. Recruitment and prevention of early dropout need attention in further development of this intervention.

TRIAL REGISTRATION

Netherlands Trial Register: NL7493. Date registered: 04/02/2019.

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.

Prenatal maternal alcohol exposure: Diagnosis and prevention of fetal alcohol syndrome

Fetal alcohol syndrome (FAS) is a developmental and congenital disorder characterized by neurocognitive impairment, structural defects, and growth restriction due to prenatal alcohol exposure. The estimated global prevalence of alcohol use during pregnancy is 9.8%, and the estimated prevalence of FAS in the general population is 14.6 per 10,000 people. In Korea, the estimated prevalence of alcohol use during pregnancy is 16%, and the prevalence of FAS is 18–51 per 10,000 women, which is higher than the global prevalence. Women’s alcohol consumption rates have increased, especially in women of childbearing age. This could increase the incidence of FAS, leading to higher medical expenses and burden on society. Alcohol is the single most important teratogen that causes FAS, and there is no safe trimester to drink alcohol and no known safe amount of alcohol consumption during pregnancy. Thus, physicians should assess women’s drinking patterns in detail and provide education on FAS to women by understanding its pathophysiology. Moreover, the prevention of FAS requires long-term care with a multidisciplinary approach.

Minimizing sample bias due to stigmatized behaviours: the representativeness of participants in a cohort study of alcohol in pregnancy

BACKGROUND

Stigmatized behaviours are often underreported, especially in pregnancy, making them challenging to address. The Alcohol and Child Development Study (ACDS) seeks to inform prevention of foetal alcohol harm, linking self-report as well as a maternal blood alcohol biomarker with child developmental outcomes. Samples were requested using passive, generic consent. The success of this approach at minimizing bias is presented comparing characteristics of women who provided samples to those who did not.

METHODS

All pregnant women in the study city were sent a Patient Information Sheet (PIS) with their first NHS obstetric appointment letter. The PIS informed them that the NHS would like to take an extra blood sample for research purposes, unless they opted out. Neither the women nor the midwives were informed that the samples might be tested for an alcohol biomarker. This paper examines the extent to which women who provided the extra sample were representative of women where no sample was provided, in terms of routinely collected information: age; body mass index; area-based deprivation; previous pregnancies, abortions and caesarians; smoking status and carbon monoxide level; self-reported alcohol use, gestation and birth weight of their baby. Chi-square and Mann-Whitney U tests were used to compare groups.

RESULTS

3436 (85%) of the 4049 pregnant women who attended their appointment provided the extra sample. Women who did not were significantly younger (p < 0.001), more materially deprived (p < 0.001), and less likely to be considered for intervention based on self-reported alcohol use (p < 0.001). There were no significant differences between the two groups on other routine data.

CONCLUSIONS

The use of passive consent without disclosure of the specific research focus resulted in a high level of sample provision. There was no evidence that study blinding was breached, and women who provided a sample were more likely to report alcohol consumption. Passive consent to draw additional blood for research purposes at routine antenatal venipuncture reduced sampling bias compared to asking women to give blood for an alcohol study. This methodology may be useful for other stigmatised behaviours.