The memory of his tiny grandson, weighing slightly over 1 pound, fighting for his life six years ago in a Florida hospital, reminds Sen. Lawton Chiles, D-Fla., of the many children who are not so lucky.

Chiles' grandson, Lawton Chiles IV, lived, but the infant mortality rate in the United States is nearly double that of Japan and higher than 16 other developed countries, according to recent statistics."First, I found out how shocking the numbers were and then I found out that the major problem is low birth weight," says Chiles. "It's a problem that we can do something about."

Low birth weight under 5 pounds, 8 ounces is considered among the major factors in infant mortality, and studies show that good prenatal care is the key to reducing the problem.

In an attempt to focus attention on the problem and come up with solutions, Chiles sponsored legislation that Congress passed last year creating the National Commission to Prevent Infant Mortality.

"Countries that don't have established neonatal clinics and that don't have any technology beat our socks off because they take care of their mothers so they have a healthy baby to start off with," Chiles says.

While the U.S. infant mortality rate the number of babies per 1,000 live births who die before their first birthday declined from 14.1 in 1977 to 10.6 in 1985, this country's position has not improved since 1980, according to the commission.

And nowhere is the problem greater than the South, where the region's infant mortality rate is 11.9 per 1,000 births, according to 1985 figures from the National Center for Health Statistics.

In addition, the infant mortality rate among blacks is nearly twice as high as it is for whites with the rate in some U.S. cities worse than that in some developing countries, the commission says.

Among the states, the District of Columbia tops the list with 20.8 deaths per 1,000 births, followed by Delaware at 14.8, South Carolina 14.2, Mississippi 13.7, Georgia 12.7 and Alabama 12.2.

"The presumption in America with its Mom and apple pie is, of course, our children are cared for," says Rae Grad, executive director of the commission. "That's not the truth. But we want to believe that myth."

The commission, which will be holding a fourth hearing in Chicago April 25 and another in May, is expected to release its report and recommendations before the Democratic and Republican national conventions, Grad says.

"We need vision and leadership, not just money," she says, to solve the problem, adding that the issue has also been raised by this year's Democratic and Republican presidential candidates.

The uninsured, the poorly educated, black, Hispanic, teenagers and those from large urban areas are the most likely to obtain insufficient prenatal care, a Government Accounting Office study says.

About 1 percent of all babies born in the United States 40,030 in 1985 die in the first year of life and nearly 66 percent of these deaths occur in the first 28 days of life, according to an Office of Technical Assessment study released in February.

For every $1 spent on prenatal care, the Institute of Medicine estimates that $3.38 is saved, according to the commission, which adds that some studies put the savings figure as high as $10.