Sudden Infant Death Syndrome is a disease that can ravage the lives of new parents by taking their new baby without warning.

Since 1990, researchers have been unraveling causes of the syndrome.

When pediatricians recommended infants sleep on their backs, the number of babies who died from SIDS fell from 130 deaths per 100,000 in 1993 to 51.6 in 2010.

Recategorizing some of those deaths to accidental suffocation and strangulation in bedding also contributed to the decrease. Pediatricians began encouraging parents to put their infants to sleep on a firm mattress without soft bedding.

Despite these recommendations, a recent study published in Pediatrics found that half of parents contacted during an annual survey conducted between 1993 and 2010 were still using soft bedding.

And it turns out there may be a neurologic cause of SIDS, according to a studyMorg published in Pediatrics in 2013. Investigators examined tissue from the brain stems of infants who died from SIDS. They examined deaths that did not involve asphyxia as well as deaths that were possibly asphyxia-related.

In both groups, the infants had neurochemical abnormalities that impaired brain stem circuits that help control breathing, heart rate, blood pressure and temperature control during sleep. The researchers think the abnormalities keep infants from waking up if they rebreathe too much carbon dioxide or become overheated.

The researchers said babies dying in unsafe sleep environments also had these same brain stem abnormalities.

The researchers encourage safe sleeping practices. Co-sleeping with your infant under 3 months remains the largest risk factor for SIDS. Doctors continue to recommend infants sleep alone in a crib with a firm mattress, a fitted sheet and warm sleepwear, free from crib bumpers, pillows, blankets and toys.

Snuggly bears can wait until toddlerhood.