MISSISSIPPI STATE -- Sudden Infant Death Syndrome claims 40 percent fewer babies since the "Back to Sleep" campaign began in 1994, but researchers still don't know why SIDS strikes 1.6 per thousand Mississippi live births.

SIDS is the No. 1 cause of death in full-term infants 1 week to 1 year old and claims about 3,000 U.S. babies each year. The death is unpredictable, but the highest numbers occur between 2 and 4 months of age. The risk declines dramatically after age 6 months.

Carla Stanford, child and family development agent with the Mississippi State University Extension Service in Pontotoc County, said SIDS babies fail to awaken from sleep for no apparent reason. While steps can be taken to reduce risks, there is no guaranteed prevention until the cause is found.

"Although researchers are learning more every day about SIDS, so much about this mysterious condition is still unknown," Stanford said. "Poor breathing conditions are thought to be possible causes of SIDS, so good prevention tactics include placing babies on their backs for rest and sleep, using firmer mattresses and not smoking around babies."

The Southern Medical Journal published a study on SIDS and the risk factors and rates in Mississippi. The state's rate is higher than the U.S. rate, and the national rate is higher than that of other industrialized countries.

According to this study, the three most likely causes of SIDS are abnormal sleep/wake regulation, temperature regulation and cardiorespiratory regulation. Each of these abnormal conditions could result in breathing problems during sleep, which could lead to death.

Parents and caregivers are encouraged to put infants to sleep on their backs as studies show that those who sleep on their stomachs are two to three times more likely to die of SIDS than those on their backs.

"The reason the prone sleep position is associated with increased incidence of SIDS remains to be satisfactorily explained," the Southern Medical Journal stated.

The journal explained that babies on their stomachs tend to sleep through more noises and have a poorer response to environmental stimuli than do babies on their backs. Researchers suggest this may mean the babies' brains are not triggered as well by low oxygen or increased carbon dioxide levels.

Other research is looking at the increased risk tobacco smoke that babies breathe seems to bring. The journal said that smoking by mothers "has been shown to be one of the most significant predictors of SIDS" and other illnesses. No one knows why this is true, but the numbers suggest a relationship.

The best news on the subject may be the possible preventative effect breast-feeding has on SIDS.

"Recent well-controlled studies have consistently shown that infants who were never breastfed were two to three times more likely to die of SIDS than their breastfed counterparts," the journal states.

Research has shown why breast milk can help protect against various diseases, but researchers don't know why it has a protective effect against SIDS.

Other factors that researchers think may play a part in SIDS are prematurity, sleeping on soft bedding and babies being too hot while they are sleeping.

The North Mississippi Council on SIDS Awareness was formed to promote education and practices that reduce the risk of SIDS. For more information on the organization, contact Stanford at (662) 489-3910.

Contact: Carla Stanford, (662) 489-3910