"One of the potential major pay-offs of this enormous technology, that the taxpayers have paid for, will be in the area of prevention, treatment and ultimately cure of birth defects," he said. "However, that will not happen if the public remains ignorant of these issues."

Kaback said the causes of birth defects are numerous. Some are environmental, such as infections. Some birth defects, such as those caused by drug use in pregnancy, come from the interaction of environmental and biological factors. Others, such as Down's syndrome, are caused by genetic factors.

Diagnosis of birth defects in the womb has improved enormously over the past 20 years, creating possibilities for prevention and treatment, Kaback said. Genetic screening has also made it possible for couples to anticipate, or avoid, conceiving a child with a birth defect.

"There isn't a single solution if we want to reduce infant mortality," said Kathy Kneer, program director for the March of Dimes of California. "It's not like polio; one vaccine won't cure infant mortality. You need a medical model, a social model and a research model."