They Mystery of Sudden Infant Death Syndrome (SIDS)

SIDS, or the Sudden Infant Death Syndrome, can be an especially horrifying way for parents to lose their infant. Infant victims of SIDS are usually between two and four months of age. Most often it occurs when the child is asleep, and having the child seated in a prone (or face down, stomach on the bed position), can increase the risk that a young infant will die from SIDS. As mysterious as the causes of this syndrome are, a public health campaign which encouraged parents to put their child to sleep on their back, called the "Back to Sleep Campaign" is credited with savings thousands of lives, according to a recent review in the New England Journal of Medicine, the Sudden Infant Death syndrome, published online at nejm.org, which attempts to review the current understanding of this mysterious medical condition.

Part of the mystery of SIDS is the search for an explanation of why the rates of SIDS deaths varies markedly from country to country around the world. For example, in Japan the mortality rate from SIDS is 0.09 deaths per 1,000 infants, while in New Zealand the mortality rate from SIDS is 0.80 deaths per 1,000 infants. In the United States, babies who are of Native American or Black ancestry, have between a two and seven times higher risk of dying from SIDS compared to a national average of 0.57 SIDS deaths per 1,000 infants in the United States.

As infants who are in the prone positions may be more vulnerable to asphyxia, this is one possible explanation for the increased mortality risk from SIDS associated with lying in the stomach down or prone position. Risk factors for SIDS include prone sleeping, sleeping on the side, using bedclothes that cover the head, sleeping on soft furniture such as sofas (where an infant could be wedged and then suffocate), a high room temperature where the baby sleeps, soft bedding and bed sharing. Indeed, a parent who sleeps with a young infant always runs the risk of moving on to an infant during a dream state and unintentionally suffocating them. Other risk factors specific to the child include prematurity, male gender, and a family history of SIDS, and having a mother who smokes.

With regards to the baby who is prone, or face down, this may cause the child to rebreath exhaled gases such as carbon dioxide, or may cause them to smoother their face when they sleep face down. Such occurrence may lead to asphyxia, which may be in the initiating event in SIDS. Currently to prevent SIDS, parents are recommended to have their infants sleep on their back on a firm mattress, alone in their own bed, but in a room with other people, and using a pacifier during sleep has been found to be protective through unknown mechanisms. Overheating should be avoided and a child should not wear a cap or bonnet to bed as a large amount of heat normally leaves the body through the head.

The presence of a fan in the room of a sleeping infant may also decrease the risk of SIDS. This may be due to improved air circulation which decreases the amount of carbon dioxide that a child rebreaths if they happen to turn over to the prone position. While more studies may be taken, this is an intervention that parents who are worried about SIDS can take, and has a reasonable explanation as to why it may provide some protection.

Sources:

H.C. Kinney, M.D. et al. The Sudden Infant Death Syndrome. The New England Journal of Medicine. Volume 361:795-805. August 20th, 2009, http://www.nejm.org.

Use of a Fan May Reduce SIDS Risk, William T. Basco, Jr. M.D. FAAP, Published 3/13/09, Medscape Today http://www.medscape.com/viewarticle/589127, Coleman-Phox K, Odouli R, Li DK Arch Pediatr Adolesc Med. 2008;162:963-968