Pneumographic studies: predictors of future apnoeas but not sudden infant death in asymptomatic infants.

Pneumograms were performed on 401 asymptomatic infants: 322 siblings, 15 cousins and 24 twins of sudden infant death syndrome (SIDS) victims; 14 siblings of near-miss SIDS victims, and 26 infants of anxious parents. The infants of anxious parents had significantly fewer abnormalities than siblings of SIDS victims. In 222 infants subsequently monitored at home, the pneumogram as a predictor of future apnoea had a sensitivity rate of 97.5% and a specificity rate of 72% (P less than 0.001). Infants who were to experience future apnoeas had a significantly higher percentage of time in periodic breathing and a higher density of apnoeas in their original pneumograms. However, the abnormal pneumogram did not predict SIDS, because the eight infants who died all had normal pneumograms.