A maturational delayin the sleep/wake pattern of male high risk for SIDS infants

Male and female infants at high risk for SIDS were compared with rigorously matched controls for sleep/wake variables. The data are based on continuous 24 to 72 hr. electrophysiological recordings repeated at monthly intervals during the peak period for SIDS. The most striking difference between risk and control infants is in the failure of male risk infants to demonstrate the expected increase in wakefulness with age. Risk male, but not female, infants also reveal a lag in the maturation of REM/NREM sleep. Significant sex differences within the first six months of life are of particular importance because of the consistently reported higher incidence of SIDS in males than females. An immature sleep/wake organization which occurs differentially in male at risk infants suggests that a functional disorder is present selectively in males as a precursor to SIDS.