Activity states in premature and term infants

Generally, studies which have compared full term infants shortly after birth with prematurely born infants tested at the date of their expected birth (i.e., 40 weeks conceptional age) have stressed the similarities rather than any differences which have appeared in the data. Nonetheless, numerous differences have been noted, and the present study documented an additional discrepancy in function between full term and premature infants at 40 weeks conceptional age as well as maturational changes in state responsivity during the premature period. Premature infants were given repeated neurological examinations at 31-33, 34-36, and 38-42 weeks conceptional age. Full term infants were tested at 38-42 weeks conceptional age. Included in the scoring of the examination were 37 measures of state, designed to assess the infant's responsivity to the increasingly stressful items of the neurological examination. The younger prematures were more often judged to be asleep and had lower scores throughout the examination when compared to the 38-42 week infants. Crying occurred significantly more often with increasing age. In addition, the full term infants had significantly more crying scores than the prematures of the same conceptional age.