2 Drinks Can Harm Unborn Baby's Brain

PAUL RECER / AP 16feb04

Just two cocktails consumed by a pregnant woman may be enough to kill some of the developing brain cells in the unborn child, leading to neurological problems that can haunt a person for a lifetime, new studies suggest.

Dr. John W. Olney, a brain researcher at Washington University in St. Louis, said his studies show that alcohol can cause nerve cells in the developing brain to commit suicide.

And, based on animal studies, it doesn't take much alcohol to have this effect, Olney reported Friday during the national meeting of the American Association for the Advancement of Science.

Two cocktails, in most women, are enough to elevate alcohol levels in the blood to 0.07 percent, he said. The animal studies show that in unborn mice this concentration is enough to kill developing brain cells.

"That amount of alcohol would cause a state of intoxication just under the legal limit, which is 0.08 percent in most states," including Washington, he said.

A single glass of wine may not be a problem, but "if one glass leads to another, and then another on the same day, that is a different matter" because it keeps the alcohol concentration at a toxic level long enough to be damaging. He said studies in mice show that just one hour at 0.07 percent is enough to kill fetal neurons.

Olney said his studies show that when neurons in the developing brain fail to make new synaptic connections, they are programmed to commit suicide, a process known as apoptosis. Making the synaptic connections, part of building a network in the brain, begins during the sixth month of gestation in humans and continues for several years after birth.

Alcohol interferes with making the new synaptic connections, causing the cells to die. And alcohol is not the only chemical that has this effect.

Olney said his mouse studies show that medical anesthetics can also cause the death of fetal neurons. So can some of the so-called "party drugs," he said.

Olney recommended that pregnant women avoid exposing their unborn to general anesthetics, even if it means delaying some surgeries until after delivery. He said the short-term use of painkilling drugs during labor does not put the fetal brain at risk.