A new study, published in the Journal of the American Medical Association, may help give insight into the causes and risks associated with SIDS, or Sudden Infant Death Syndrome, a disease that every year kills more than 2,300 babies before their first birthday — and strikes fear into the hearts of many parents.

According to the study, babies who die from SIDS make low amounts of the message-carrying brain chemical serotonin needed to regulate sleep, breathing and heart rate. The study found that abnormal levels of serotonin may hamper an infant's breathing, particularly in situations such as breathing in too much exhaled carbon dioxide while sleeping face down. Researchers found that serotonin levels were 26 percent lower in tissue from babies who died of SIDS than those who died from other causes, and they also found low levels of the enzyme tryptophan hydroxylase, which is needed to make serotonin.

Health experts have known for years that certain risks, such as exposure to secondhand smoke, and sleeping face down, exacerbate the possibility of SIDS. But these most recent findings suggest that some babies have an underlying vulnerability to SIDS, which can become fatal when combined with an external stress such as sleeping face down, especially when it occurs within the first year of life.

Ideally, this research will lead to a test that can give parents an early warning sign for kids who need extra care and attention during that vulnerable first year ... helping kids (and their parents) breathe a little easier.