A recent study by UW-Madison scientists provides more evidence that women who might be pregnant should pass on happy hour.
In a study published last month in the journal Alcoholism: Clinical and Experimental Research, UW-Madison developmental biologist Susan Smith and researchers Ana Garic-Stankovic and Marcus Hernandez report on their discovery of the precise mechanism by which alcohol kills cells in a developing embryo.
\Alcohol causes the cells to spew out their calcium. It floods the cells. That's not normal,"" Smith said.
The researchers discovered that prenatal alcohol exposure triggers certain cells to release toxic amounts of calcium that kill the embryonic cells that will later become facial features and brain cells.
Calcium controls various cellular processes and cells normally release very small controlled amounts. But when an embryo is exposed to alcohol, ""the calcium gates open indiscriminately,"" according to Smith.
The UW team injected chicken embryos, equivalent in age to 20-day old human embryos, with alcohol to examine the prenatal effects. They observed alcohol-caused cell death in a stage of gestation so early that many women would not yet know they were pregnant.
And even small amounts of alcohol-the equivalent of a couple of drinks in one hour-released the calcium floods that killed brain cells, Smith said.
""Even low intakes of alcohol can turn on this cell death pathway,"" Smith said. ""This is why we tell women of childbearing years that you need to think about your alcohol consuming behavior.""
The UW team also found that prenatal alcohol exposure activates the chemical pathways of alcohol addiction. While the scientists were intrigued by the findings, more research is needed to determine whether prenatal alcohol exposure could lead to alcohol addiction later in life.
According to Smith, her study should not lead women to panic if they discover they have consumed alcohol in early pregnancy. The sooner a pregnant woman stops drinking, the sooner the embryo can repair damaged cells.
""The embryo has a tremendous ability to repair damage,"" she said.
How much and how often pregnant women drink alcohol determines the severity of cell death for the fetus. The study showed that more alcohol will kill more cells, so binge drinking poses serious risks to an embryo or fetus.
Although a pregnant binge drinker or alcoholic will cause the most damage to a fetus, no level of alcohol consumption has been proven safe during pregnancy, according to the March of Dimes, a research, education and infant health advocacy organization.
Marie Crist, Wisconsin's March of Dimes program director, said that is why the organization recommends pregnant women absta in from all alcohol.
""Don't drink. There's just no sense in taking the chance,"" she said.
