Sudden Infant Death Syndrome, or SIDS, is the leading cause of death in infants under 12 months. While the exact cause has yet to be identified, sufficient evidence indicates that SIDS is primarily a physiological problem. A study just published in the Journal of the American Medical Association (JAMA) further supports this theory. The study found that babies who died from SIDS have lower amounts of the neurotransmitter (brain chemical) serotonin.
The study was based on data collected between 2004 and 2008 from forty-one infants who died from SIDS, seven infants who died from unknown causes, and five hospitalized infants with chronic hypoxia-ischemia.
In the infants that died from SIDS, serotonin levels were 26 per cent lower than in those of babies that died from other causes. This may be the missing physiological link researchers have been looking for.
Serotonin regulates sleep, heart rate and breathing. It acts as an "alarm system" to wake up the baby when breathing is disrupted. An infant's sleep cycle is approximately twenty minutes. Babies with reduced serotonin levels may not be aware that they are not breathing enough oxygen, causing them to sleep longer and potentially die in their sleep.
The next step is to determine why some babies have reduced levels of serotonin.
Currently, there is no test to determine which infants may be at risk for SIDS. In the meantime, to reduce the risk of infant death, parents are advised to ensure optimal air flow in the room where the baby is sleeping. Babies should sleep on their back not on their tummy to avoid rolling over and suffocating. Keep babies warm, but not hot, and ensure the crib is free of pillows, blankets, loose bedding, toys, pets or anything else that can inhibit their breathing.
Duncan, J., Paterson,D., Hoffman, J., Mokler, D., Borenstein, N., Belliveau, R., Krous, H., Haas, E., Stanley, C., Nattie, E., Trachtenberg, F., Kinney, H. "Brainstem Serotonergic Deficiency in Sudden Infant Death Syndrome"(2010) JAMA, 303.