Expectant mothers may unknowingly put their unborn child at risk if they consume large amounts of alcohol in the early stages of pregnancy. This article explores new research that sheds light on the molecular changes in the placenta caused by rapid alcohol exposure, and how these changes could have significant consequences for the child’s development. Placenta and DNA methylation play crucial roles in this process.
Unplanned Pregnancy and Alcohol Exposure
Approximately half of all pregnancies are unplanned, and alcohol consumption among women is on the rise globally, according to the World Health Organization. This means that many women may unknowingly expose their developing embryos to high levels of alcohol, particularly in the early stages of pregnancy.
The new study, led by Serge McGraw, an associate professor at the Université de Montréal and a researcher at the university’s affiliated children’s hospital, CHU Sainte-Justine, aimed to shed light on the effects of this rapid alcohol exposure. Using a mouse model, the researchers observed significant molecular changes in the placenta, including the expression of numerous genes and DNA methylation, an epigenetic marker that influences gene expression.
Placenta’s Role in Fetal Development
The placenta plays a central role in the development and health of the fetus, so the changes observed in the study could have major consequences for the child’s future. The researchers believe that these DNA methylation alterations could provide a robust molecular signature for detecting alcohol exposure in early pregnancy, paving the way for the development of diagnostic tests in humans.
Interestingly, the epigenetic impact of alcohol exposure varies by sex. In male embryos, the regulation of growth-related genes was more affected, corroborating data showing that males are more vulnerable to growth retardation after preimplantation exposure to alcohol. In females, it was mainly the regulation of genes involved in the metabolism of serotonin, an essential neurotransmitter for brain development and function, that was affected.
Implications for Early Intervention and Prevention
These findings suggest that a disruption in the serotonin signaling pathway could contribute to the morphological defects in the brain that were observed in the mouse model. The researchers believe that DNA methylation profiles could be a good indicator of whether a baby has been exposed to alcohol during gestation, which could lead to the development of a screening test.
Currently, there is no molecular diagnostic test for prenatal alcohol exposure, and difficulties often go unnoticed until school age or even adolescence. A screening test based on the molecular memory of exposure found in the placenta could ensure appropriate medical follow-up from an early age, allowing for timely intervention and prevention of potential developmental issues.
