Abstract â–¡ 4

Clinical and laboratory surveys confirm that infants who eventually became victims of SIDS had an unexpected high frequency of mixed and obstructive sleep apneas. The number of such obstructed breaths is significantly lower in age and sex matched control subjects. The events are associated with drops in blood oxygen contents and with falls in heart rates. Several factors also known to increase the risk for SIDS have also been shown to increase the frequency of mixed and obstructive apneas in healthy infants. Such apnea-promoting risk factors include a previous sleep deprivation, the use of sedative drugs, prenatal smoking, or high environmental temperature. Infection diseases further increase the frequency and the duration of the obstructive and mixed sleep apneas. The prolonged drops in transcutaneously measured blood oxygen saturation, and in heart rate recorded in some infants who died of SIDS could result from the effects of obstructive breathing events.