The sudden infant death syndrome (SIDS) is the leading cause of infant mortality in developed countries. The risk is greatest in the first six months of life while the autonomic nervous system matures to control the homeostatic functions of respiratory drive, blood pressure regulation, temperature, airway reflexes and arousal. It appears that the functioning of these mechanisms requires serotonin (5 hydroxytryptamine 5HT) to be normally produced, released and cleared in the region of the medulla and brain stem. Where this is not achieved, the risk of SIDS rises, as found in post-mortem demonstrations of excess 5HT by a Californian group led by Paterson (JAMA 2006;296:2134-32).
They showed that 5HT dysregulation was a neuro-chemical abnormality far more frequently found in SIDS victims than controls which may explain an underlying vulnerability and partially explain the male predisposition. Wease-Mayer in an editorial (pp 2143-4) alludes to the preventable factors in SIDS, namely putting all children to sleep on their backs on firm surfaces, avoiding soft bedding and overheating, as well as reducing exposure to antenatal or postnatal smoking. It was found in a recent US survey that two-thirds of children succumbing to SIDS were sleeping prone when they died, so it is time to re-launch the “Back-to-Sleep” campaign.
