Developmental lags in preterm infants from one to three years of age.

Assessments of play, sensorimotor, language, and general developmental skills were administered to 20 preterm and 20 full-term infants at comparable corrected and postnatal ages in 5 sessions during the second and third years of life. Clear effects of biological maturity on play and sensorimotor skills were demonstrated at 13 1/2 months, and less pervasive effects remained at 22 months. Furthermore, the preterm infants were significantly delayed in sensorimotor, personal-social, and gross motor abilities at 13 1/2 months and in language abilities at 22 months beyond that predicted by biological maturity alone. While these deficits were mostly overcome by 3 years, the preterm infants performed somewhat more poorly on visual information-processing tasks. This investigation demonstrated that the development of representational abilities as manifested in play and sensorimotor behaviors was clearly related to corrected age rather than postnatal age.