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Sudden infant death syndrome (SIDS) refers to cases of abrupt infant death where no cause of death can be identified even after an exhaustive investigation. While the exact causes of SIDS remain unknown, it is generally agreed upon by the medical community that a combination of three types of factors is to blame for deaths attributed to this syndrome. Specifically, research suggests that an infant must have certain biological susceptibilities in their brains. The presence of one of these biological susceptibilities makes infants vulnerable to potential environmental factors that are known to trigger SIDS such as stomach sleeping and wearing too much clothing. An underlying biological vulnerability and an environmental trigger can result in SIDS when the infant is in a crucial period of development.
Research illustrates that the risk of an infant dying from SIDS is low immediately after birth but begins to rise in the first month and peaks between two and four months, then begins to diminish entirely. This suggests that infants who suffer from SIDS are in distinct stages of development that somehow make them more vulnerable to the disorder. During this time, if other hypothesized SIDS causes are present, an infant has a high likelihood of experiencing sudden death.
One of the other hypothesized SIDS causes is a developmental delay in brain functioning. Researchers have found that infants that suffered from SIDS had abnormal development of the portions of the brain that control heart and lung function. It is generally agreed that these portions of the brain are responsible for initiating what is know as the arousal response. The arousal response is the body’s ability to wake itself upon the presence of an external stimulant, such as when breathing is obstructed.
When an infant suffers from a biological brain susceptibility that prevents them from waking up when stimulated and at the same time, falls into a critical stage of development, the presence of certain outside environmental factors can trigger a case of SIDS. These environmental SIDS causes include sleeping face down, the abundant use of blankets and other bedding, and overdressing. When an infant sleeps face down or surrounded by a lot of soft blankets and bedding, often his mouth and nose area can easily become covered. Without the ability to rouse when they are unable to breath, these infants are particularly vulnerable to what is referred to as re-breathing asphyxia, which occurs when there is little air movement around the nose and mouth and an infant re-breathes the carbon dioxide that they recently exhaled. This results in oxygen deprivation, and, ultimately, can lead to death.
Overdressing an infant with a neurological susceptibility at a time when they are at a vulnerable developmental stage can also prove fatal. Too many clothes can obstruct the airway and also cause re-breathing asphyxia. It is also possible that the increased temperature that results from overdressing can cause these infants to lose control of their breathing, resulting in their sudden death.
There is not one underlying identifiable cause of SIDS. Rather, there are multiple SIDS causes that must be present in order for sudden death to occur. When developmental vulnerabilities and environmental triggers occur during a crucial stage in development, an infant is at an increased risk of suffering from SIDS.