Postnatal Maturation of Small Intestinal Motility in Preterm and Term Infants

Perfusion manometry was used to study the maturation of small intestinal motility in 15 preterm and term infants before the initiation of enteral feeding (study 1); seven of the 11 preterm infants were restudied after 3 weeks or more of enteral feeding (study 2). During study 1, the interdigestive motility of the four term infants exhibited cycles of quiescence and rhythmic activity, compatible with migrating motor complexes observed regularly in adults; in response to feeding, motility changed to irregular, phasic activity. Preterm infants, however, showed only unorganized clusters of phasic activity during fasting, and there was no consistent pattern of motor response to feeding. After 3 or more weeks of enteral feeding, interdigestive cycles with migratory motor complexes and a consistent, obvious motor response to feeding were present. Preterm infants as young as 32 weeks' gestation showed "mature" motor patterns in study 2, results suggesting that intestinal motility matures with postconceptual age.