Gestational and postnatal maturation of duodenal motor responses to intragastric feeding

Objective: Continuous perfusion manometry was performed in 93 preterm and 14 term infants, none of whom had ever been fed enterally, to determine whether duodenal motor responses to bolus feeding differ in preterm and term infants. Study design: Motor activity was recorded for 6 hours: 4 hours before and 2 hours after an intragastric feeding composed of Similac Special Care Formula, 5 ml/kg, infused for 15 minutes. Results: Although 12 of 14 term infants had an increase in duodenal motor activity postprandially, similar to that seen in adults (i.e., a mature fed response), only 32 of the 93 preterm infants did (chi square statistic=13.2; p <0.001). In contrast to these infants, 2 term and 77 preterm infants had a decrease in duodenal motor activity (i.e., an immature fed response). There was a significant increase in the number of peaks per 30 minutes in the postprandial recordings of infants who demonstrated the ''mature fed response'' and a significant decrease in the number of peaks per 30 minutes in the postprandial recordings of infants who had an ''immature fed response'' (all p <0.05). We then reevaluated motor responses to feeding among 41 of the preterm infants after they had received small enteral feedings of 24 ml/kg per day for 7 to 10 days. Although 11 of these infants had exhibited a mature response at the time of their initial study, 25 did at the time of the second study (p <0.03). Conclusion: The duodenal motor response to bolus feeding differs in preterm and term infants; however, with enteral feeding experience, preterm infants begin to demonstrate more mature duodenal motor responses to feeding.