Fetal Alcohol Syndrome: How Prevalent Is It?
Tuesday, March 15, 2011
There are few things more dangerous to a fetus than alcohol. Drinking alcohol during pregnancy is one of the leading causes of birth defects.
Babies who are born with fetal alcohol syndrome have physical abnormalities and face a lifetime of learning and behavioral problems. Surprisingly, doctors don't know how prevalent the condition is.
SAN DIEGO There are few things more dangerous to a fetus than alcohol. Drinking alcohol during pregnancy is one of the leading causes of birth defects.
Babies who are born with fetal alcohol syndrome have physical abnormalities and face a lifetime of learning and behavioral problems.
Surprisingly, doctors don't know how prevalent the condition is.
Alcohol consumption during pregnancy is the leading preventable cause of mental retardation and birth defects.
Despite all the warnings about the problem, a recent government survey found one out of 12 pregnant women drink, and about one in 30 binge drink.
In 1973, pediatrician Kenneth Jones and a colleague were the first to describe fetal alcohol syndrome.
In his Kearny Mesa office, Jones recently examined a 3-month-old girl suspected of having the disorder.
This baby was born in a motel room. Her mother admitted to drinking during her pregnancy. The baby was taken away and placed in foster care shortly after she was born.
Jones looked for some of the telltale physical signs of fetal alcohol syndrome. He quickly found one.
"I don’t know if you've noticed this," the pediatrician told the foster mom, "but she has only one crease on her fifth finger. You see that?"
Jones noticed another distinctive feature: The space between the baby's upper lip and nose is totally flat.
He also looked for some behavioral clues. Irritability and an over-sensitivity to sound are indications of exposure to alcohol.
After a few minutes, Jones finished the exam.
"She clearly does not have the full-blown fetal alcohol syndrome," Jones explained. "She has some features that are consistent with that condition."
Jones said that when he first identified fetal alcohol syndrome, it was thought that children either had the full condition or showed no effects at all. It's now believed exposure to alcohol causes a broad spectrum of defects.
Jones said doctors don't know much about the mildest end of the spectrum.
"So for example," Jones said, "could we be seeing children who've been prenatally exposed to alcohol who are completely normal from a structural standpoint, who are completely normal in terms of their growth, but have neuro-behavioral problems? And is that due to the effect of alcohol on the developing fetus? And at this point, that's what we are most interested in in trying to understand."
Alcohol affects the fetal brain in a number of ways.
Dr. Doris Trauner is chief of UCSD's division of pediatric neurology.
"It causes death of the nerve cells as they're developing," Trauner said. "It also causes the nerve cells that are there that don't die, to not develop normally. So they don't develop the normal connections from one nerve cell to another."
Trauner said a lot of damage from drinking can occur in the baby's first trimester.
That's especially troubling because the average time a woman finds out she's pregnant in the United States is at six weeks. Heavy drinking episodes before that point can put the baby at risk.
There are no reliable estimates about the prevalence of fetal alcohol syndrome.
That's because it's hard to diagnose.
Few women will admit they were drinking during their pregnancy. Most babies affected by alcohol use have no obvious physical characteristics. And they don't usually display any cognitive problems until the first grade.
To get a better handle on the condition, a new study will soon be launched in San Diego and in three other U.S. cities.
The San Diego Unified School District and the foster-care system will screen up to 3,000 children for the disorder over the next five years.
UCSD's Dr. Tina Chambers is heading up the study.
"If we can establish a prevalence of this disorder," Chambers said, "and it's as substantial as we think it is, we think it's probably as common as autism, then that in turn might be a real motivating factor for health care providers, educators, and families to address this problem a lot more seriously."