Review Highlights Advances in Understanding Sudden Infant Death Syndrome

Kinney HC, Thach BT. 2009. The sudden infant death syndrome. The New England Journal of Medicine 361(8):795-805.

"Current evidence suggests that SIDS (sudden infant death syndrome) involves a convergence of stressors that probably results in asphyxia of a vulnerable infant who has defective cardiorespiratory or arousal defense systems during a critical developmental period when immature defense mechanisms are not fully integrated," state the authors of an article published in the August 20, 2009, issue of The New England Journal of Medicine.

SIDS has been substantially demystified in recent years by major advances in our understanding of its relationship to sleep and homeostasis, environmental and genetic risk factors, and biochemical and molecular abnormalities. However, SIDS still remains the leading cause of postneonatal infant death in the United States and is the third leading cause of infant mortality overall. This review highlights the major advances in our understanding of SIDS.

Topics include the definition and incidence of SIDS, causes of sudden and unexpected infant death, newer models for SIDS, risk factors for SIDS, putative terminal pathways for SIDS, and asphyxia-related sudden deaths. Recommendations for risk reduction and counseling are also presented.

The authors found that risk-reduction recommendations include putting infants to bed in the supine position on a firm mattress, preferably with a pacifier (mechanism unknown) and in a shared room (but in a separate bed). Important counseling strategies for families with infants who have died of SIDS have been devised. Of major concern in such families is the risk of SIDS in subsequent siblings. Although in such cases there is an increase in risk, it is minimal.

"Our current understanding of the pathogenesis of SIDS reflects the simultaneous juxtaposition of multiple events that, when taken individually, are far less powerful than the result of their chance combination," state the authors. They conclude that "SIDS remains a major problem that mandates continued interdisciplinary efforts for its ultimate resolution."

Extract available at http://content.nejm.org/cgi/content/short/361/8/795??eaf