State organization in neonates: developmental inconsistency indicates risk for developmental dysfunction.

Twenty-two healthy full-term infants were observed for 7 continuous hours in their homes weekly on weeks 2, 3, 4, and 5. Code recordings of their behavioral states and any mother-infant interactions were made every 10 seconds. An analysis was made of the distribution of the infant's state behaviors during the time it was left alone (mean = 279.6 minutes in 7 hours). The states were Waking Active, Quiet Alert, Fuss or Cry, Drowse or Transition, Active Sleep, and Quiet Sleep. Four state profiles were obtained for each infant, one for each week of observation; then a single quantitative measure of profile consistency over weeks was calculated. Infants with the four lowest profile consistency indices had major developmental problems between 3.5 and 30 months (p less than .001): one had aplastic anemia; a second had hypsarrhythmia, a third died of SIDS, and the fourth was hyperactive, both at home and in a testing situation. Other infants with low consistency scores showed minor developmental delays at 6 months and at 30 months. None of the infants at the upper end of the consistency continuum showed evidence of any developmental dysfunction by 30 months of age. The findings indicate that developmental inconsistency in state organization during the neonatal period is predictive of risk for later development.