Study of a group of extremely preterm infants (25-27 weeks): How do they function at 1 year of age?

The functional outcome of 49 extremely preterm infants (gestational age: 25-27 weeks) was studied at the corrected age of 12 months. Apart from pediatric follow-up, a full neurologic assessment and the Bayley Motor and Mental Scales of Infant Development was done. Emphasis was placed on postural control, spontaneous motility, hand function, and elicited infantile reactions. Special attention was given to symmetric development. The infants were then categorized as having optimal or nonoptimal or asymmetric outcome. Overall, an optimal outcome was found in 19 infants (39%) and nonoptimal outcome in 30 infants (61%), 7 of whom failed on all domains of function. Postural control had a significant influence on the different domains of development such as motility (P less than or equal to .001) and persistent infantile reactions (P less than or equal to .001) and slightly less on hand function (P=.08) and asymmetry (P=.06). The outcome on spontaneous motility was significantly related to the results on infantile reactions (P less than or equal to .005) and hand function (P=.05). Also, the score on the motor scale of the Bayley Developmental test was clearly related to outcome on spontaneous motility (P less than or equal to .001) and reactions (P less than or equal to .02). Abnormal brain ultrasonograms were related to the asymmetry of the infantile reactions (P less than or equal to .05). Poor coordination of gross motor function will have consequences for appropriate visuomotor and sensorimotor integration, thereby hampering motor learning and later cognitive function, as is often described in preterm infants. It is suggested that the poor postural control found in many infants born preterm is the result of both myogenic and neurogenic deviations caused by the preterm birth and its nursing consequences.