Five early milestones in premature infants.

The onset of five early milestones was studied in premature and full-term infants. The milestones are: recognition of mother's voice and face, 3-month smile, following through 180 degrees, and two hand-eye coordination. It was hypothesized that premature infants would show delay in acquiring milestones related to time separated from mother. Compared to full-term infants, the prematures had a significant difference in the means only for the onset of smiling, and no effect related to maternal separation.