Current research has revealed potential new insight into why sudden infant death syndrome (SIDS) may occur. Scientists have determined that babies who die from SIDS appear to make lower quantities of serotonin, a neurotransmitter that regulates sleep, breathing, and heart rate. The information may help to identify at-risk infants and will hopefully lead to proper steps to reduce the incidence of SIDS.

Serotonin is a molecule that is responsible for communication between neurons. It is made primarily in the brain, where it performs many of its functions, influencing such things as our sleep patterns, moods, memory, and sexual desire. However, because its distribution throughout the body is widespread, serotonin is also believed to play a role in numerous bodily functions that include our cardiovascular function, our muscles, and our endocrine system. Serotonin is also believed to be a factor in breast milk production, and now, possibly in the occurrence of SIDS.

In order to arrive at the most recent findings, published in the Journal of the American Medical Association (JAMA), doctors compared neural tissue between babies that had died from various causes. Focusing on the medulla region, which is responsible for regulating basic bodily functions like breathing and heart rate, researcher found that when babies died from SIDS, they had levels of serotonin that were 26% lower than those who died from other causes. There was also a low level of an enzyme needed to make serotonin, tryptophan hydroxylase.

Scientists are not sure of the exact role that serotonin plays in SIDS, but some believe that the lower levels may inhibit a baby’s breathing. This situation could become lethal when the child’s vulnerability is increased, especially when their access to fresh air is compromised. It is for this reason doctors recommend that babies sleep on their backs for the first year of life, a practice that has become the single most effective way to lower a child’s chances of dying of SIDS. The authors hope that the results will lead to the development of a test to measure serotonin levels in newborns, thereby identifying babies with an increased risk for SIDS.

Over the past 25 years, increased awareness and vigilance have resulted in a decline in SIDS rates by over 50%. However, SIDS still claims the lives of over 2300 babies each year in this country, and it is the leading cause of death in children between the ages of one month and one year.

While the exact cause of SIDS is still unknown, certain steps recommended by the National Institutes of Health (NIH) have been shown to reduce the incidence, including putting your baby to bed on his or her back, placing them on a firm sleep surface (remove soft objects like loose bedding or pillows, especially away from their faces), and not letting your baby overheat.

If you have concerns about SIDS, talk to your pediatrician, and spend some time at the website for the National Institute of Child Health and Human Development, a division of NIH.