Neonatal functioning and the sudden infant death syndrome

A male infant, diagnosed as a Sudden Infant Death Syndrome (SIDS) at 5 months, 3 weeks, had been extensively tested as a part of a larger sample in a longitudinal study. The longitudinal sample was comprised of 137 clinically normal neonates, born to intact upper middle-class families, living in a large metropolitan area. A neonatal assessment consisted of 5 hours of polygraphic recordings of heart and respiratory rate during sleep and waking cycles, and 1 hour of behavioral testing. At 3 months of age the infant was observed for 12 hours in the home. Retrospective analyses of these data suggested that: (a) neonatal respiratory behavior during sleep did not distinguish this infant from a sample of control infants; (b) the infant lacked strength in movements requiring the involvement of shoulder and neck muscles (head lift from a prone position); and (c) informal observations by skilled and experienced observers distinguished this infant from the sample of controls.