Trying to having a baby? You might want to hold off on that evening cocktail -- even if you're not sure whether you're pregnant yet.
While we all know that drinking during pregnancy can inflict long-lasting damage on a baby, the effect of alcohol on a developing embryo before a woman knows she's pregnant has been less studied.
Now, provocative new research on mice suggests that a mother's drinking -- even in the first three weeks of pregnancy -- may create changes in the genes of the embryo that can cause permanent damage.
In light of the findings, the researchers suggest that women would be wise to cut back on drinking, or avoid alcohol altogether, as soon as they make the decision to get pregnant.
"Our findings suggest that alcohol can harm fetus in early pregnancy, a time period when women are often not aware of their pregnancy," Dr. Nina Kaminen-Ahola, a biologist at the University of Helsinki and the study's lead author, told The Huffington Post in an email. "Therefore it would be good to decrease the alcohol consumption as soon as one plans to have a baby."
However, it's too early to say how much alcohol consumption it would take to harm a human fetus during early pregnancy, and more research is needed in order to provide specific guidelines. "It is important to remember, that this is a mouse, not a human study," Kaminen-Ahola said.
In the study, the researchers fed alcohol to female mice who were at a stage of pregnancy that is equivalent to three to four weeks of human pregnancy. They found that the mice pups exhibited symptoms similar to human fetal alcohol syndrome, including hyperactivity, decreased growth rate and structural changes to the face and skull.
The early exposure to alcohol created changes in the embryo's epigenome -- the set of chemical compounds that regulate the genome -- which led to alterations in the expression of genes in the brains of the infant mice. These changes were observed in the hippocampus, a brain region associated with learning, memory and emotion that is known to be heavily affected by alcohol. Researchers also found changes in the bone marrow of the infant mice, and in some tissue within the mouse's snout that plays a role in the sense of smell.
Why did the alcohol exert such a significant and long-lasting effect on the tiny mice? The researchers explained that early pregnancy is a critical time for cell division and differentiation. The embryo is vulnerable to external influences at this stage, and any changes can become widespread because the cells are rapidly dividing.
Therefore, the effects of alcohol on the embryo "cause life-long changes in brain structure, function, and behaviour," Kaminen-Ahola said.
The researchers said that the findings may eventually be used to help diagnose, and hopefully treat, alcohol-induced damage in infants.
"Ideally, a swipe sample from inside the mouth of a newborn could reveal the extent of damage caused by early pregnancy alcohol exposure," Kaminen-Ahola said in a statement.