A new study led by Pr. Serge McGraw, researcher at CHU Sainte-Justine and professor at Université de Montréal, shows that the effects of alcohol exposure on an embryo prior to implantation in the uterus can be detected in the late-gestation placenta. Using a mouse model well suited for this type of exposure, the researcher and his team observed significant molecular changes in the placenta, including the expression of numerous genes and DNA methylation, an epigenetic marker that influences gene expression by acting as a switch.

Since the placenta plays a central role in the development and health of the fetus, these changes could have major consequences for the child's future. The study also shows that these DNA methylation alterations could provide a robust molecular signature for detecting alcohol exposure in early pregnancy. This proof of concept paves the way for the development of diagnostic tests in humans enabling early detection of alcohol exposure from the very first days of a newborn's life.

Different impacts depending on sex For a long time, it was thought that exposure to alcohol during the preimplantation phase-;when the fertilized oocyte goes from a single-cell to an embryo of a hundred or so cells-;had no effect on the unborn baby, provided the embryo succeeded in implanting in the uterus. However, over the last few years, Serge McGraw's team has demonstrated that this isn't the case. The young embryo may survive this exposure, but brain development may be .