NASHVILLE - Hoping to catch more health issues before a baby is sent home from the hospital, a new screening is being administered to all newborns in the state.

Dr. Michael Warren, director of family health and wellness for the Tennessee Department of Health, says the pulse oximetry screening was added at the first of the year.

"Before babies leave the nursery, they get a test that checks the oxygen saturation in their blood," he said, "and that can be a clue that they may have a serious congenital heart disease. Now, it's still not going to pick up every baby with serious congenital heart disease, but it will help us fill that gap of babies who weren't previously diagnosed."

It's estimated that about 4,000 babies born in Tennessee each year have some type of birth defect.

Not a lot is known about the causes of most birth defects, but Warren cited a number of ways that women can cut their risk.

"There's no safe amount of alcohol or tobacco during pregnancy," he said. "We know that some infections and illnesses can lead to birth defects, and for women who may have chronic disease like diabetes it's really important to have that disease under control (and) also for women to talk to their doctors about the medication they're taking."

Birth defects are the leading cause of infant deaths in the United States, and congenital heart defects are the most common type.