This is a summary of the recent article The association between prenatal alcohol consumption and preschool child stress system disturbance that is featured in CanFASD’s Top FASD Articles of 2020. For a complete understanding of the subject matter, read the full paper (available open access).

Background

Approximately 10% of women worldwide report drinking alcohol during pregnancy. This statistic is concerning given the relationship between prenatal alcohol exposure (PAE) and potential developmental challenges such as cognitive and behavioural impairments. Researchers have previously explored the underlying mechanisms of PAE to assist with more reliable diagnosis of PAE-related impacts.  

Notably, researchers have identified some biomarkers, especially for fetal alcohol exposure, that may influence child development. One of these biomarkers is minor ethanol metabolite (EtG), which can be detected in the infant’s first stool 72 hours after birth and contains the by-products from the twentieth week of pregnancy until birth. The purpose of this German study was to examine EtG and basal cortisol activity (baseline stress) in preschoolers aged 6-9 years to determine if EtG could be an effective biomarker of PAE. 

Main Findings

EtG levels from 137 women in their third trimester of pregnancy were tested at the Department of Obstetrics and Gynecology in Germany, of which 35 women had self-reported alcohol consumption. A follow up assessment occurred 6 to 9 years later, during which women were instructed to collect five saliva samples from their children within a 24-hour period to assess children’s cortisol activity. At the same time, a hair sample was also collected to test for cortisol activity, and child emotional and behavioural problems were assessed using a parent-report questionnaire.  

• EtG levels were detected at about 4 times higher than mother self-reports. 
• Higher levels of EtG in newborns were correlated with less cortisol activity, and the cortisol awakening response (CAR) being the most consistent measure of cortisol activity. The CAR is the difference between cortisol levels the first and the second time that saliva was taken from the child during the 24-hour period. 
• Cortisol levels in children who were exposed to alcohol prenatally were consistently lower than children not exposed to alcohol prenatally, which was especially notable in hair cortisol concentration (HCC).  
• EtG was deemed to be an effective biomarker and supports previous findings that it can be used to predict child development. 
• Additionally, high cortisol levels at bedtime, stable saliva cortisol concentrations, and low hair cortisol concentrations were related to increased child emotional and behavioural symptoms (e.g., ADHD). 

Implications

EtG may be used in some settings as a biomarker to better understand child development. Although more research should be done in this area, the authors of this study helped to clarify a potential pathway for understanding the underlying mechanisms of PAE and child development. Additional research in this area will support the development of methods for early screening, assessment, and diagnosis to identify children with PAE as well as potential targets for intervention. It is important to note that: 

• Researchers have yet to determine the amount of PAE that may lead to altered cortisol levels, and more research should be conducted to understand this relationship. 
• Researchers also note that cortisol levels are related to age in the development of all children with cortisol decreasing as the child gets older. These individual differences in child development could limit the ability to apply the use of cortisol concentration as an effective technique in identifying PAE. 
• The study’s sample was too small to find statistically significant results and the researchers note that the results should be interpreted with caution.  
• Research examining the relationship between EtG and maternal self-report for alcohol consumption may be challenging due to self-report bias. This stigma that still exists regarding disclosing alcohol use during pregnancy could prevent researchers from accurately understanding the relationship between PAE to EtG levels. 
• Presence of additional factors (e.g., child sex, age, birth weight, socioeconomic status, and maternal psychopathology) should be tested to confirm whether they influence the relationship between EtG levels and PAE. 

Authors: Jennifer Grimm, Mark Stemmler, Yulia Golub, Eva Schwenke, Tamme W. Goecke, Peter A. Fasching, Matthias W. Beckmann, Oliver Kratz, Gunther H. Moll, Johannes Kornhuber, Anna Eichler 

Journal: Developmental Psychobiology 

Date: October 2020 

Read the full article (available open access)