Causal theories suggest that the infant may have immature or hypersensitive lungs, may have a defect in brain-stem control of breathing, or may be rebreathing carbon dioxide. Recent studies have shown persistent high levels of an infant form of hemoglobin in babies with known risk factors for the condition.
SIDS victims are thought to have brief episodes of apnea (breathing stoppage) before the fatal one. An alarm system that detects breathing abnormalities is sometimes used with infants suspected of being prone to SIDS. The American Academy of Pediatrics has recommended that babies be laid to sleep on their backs or sides.
Unexpected death of an apparently well infant. It occurs almost always during sleep at night and usually at 2–4 months of age. Sleeping facedown and exposure to cigarette smoke have been implicated. It is more common in cases of premature birth, low birth weight, and poor prenatal care. Many cases that would once have been labeled SIDS prove to be due to suffocation in bedding or overheating. Some babies who die of SIDS have been found to have brain stem abnormalities that interfere with their response to high levels of carbon dioxide in the blood.
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