REM sleep prevents sudden infant death syndrome.

Near-miss events were observed to occur in indeterminate sleep in a preterm infant reaching term at 6 weeks after birth. Moreover, prolonged sleep apnea and periodic respiration were frequently encountered in non-REM sleep. In view of the observation that pathologic sleep apnea occurs in non-REM sleep and the apparently contradictory findings of respiratory depression and more frequent apneas during REM sleep, apneic episodes during REM sleep were analysed in relation to phasic REM events. The frequent occurrence of respiratory pauses in REM burst-free periods of REM sleep suggests that tonic REM mechanisms inhibit respiratory neurons, while phasic REM mechanisms are facilitatory and protect an infant from prolonged sleep apnea.