Interstage feeding and weight gain in infants following the Norwood operation: can we change the outcome?

Background: Poor weight gain is common in infants after Stage I Norwood operation and can negatively impact outcomes. Objectives: The purpose of this study was to examine the impact of feeding strategy on interstage weight gain. Methods: In a multi-centre study, 158 infants discharged following the Norwood operation were enrolled prospectively. Weight and feeding data were obtained at 2-week intervals. Differences between feeding regimens in average daily weight gain and change in weight-for-age z-score between Stage I discharge and Stage II surgery were examined. Results: Discharge feeding regimens were oral only in 52%, oral with tube supplementation in 33%, and by nasogastric/gastrostomy tube only in 15%. There were significant differences in the average daily interstage weight gain among the feeding groups - oral only 25.0 grams per day, oral/tube 21.4 grams per day, and tube only 22.3 grams per day - p=0.019. Tube-only-fed infants were significantly older at Stage II (p=0.004) and had a significantly greater change in weight-for-age z-score (p=0.007). The overall rate of weight gain was 16-32 grams per day, similar to infant norms. The rate of weight gain declined over time, with earlier decline observed for oral-and oral/tube-fed infants (less than 15 grams per day at 5.4 months) in comparison with tube-only-fed infants (less than 15 grams per day at 8.6 months). Conclusion: Following Stage I Norwood, infants discharged on oral feeding had better average daily weight gain than infants with tube-assisted feeding. The overall weight gain was within the normal limits in all feeding groups, but the rate of weight gain decreased over time, with an earlier decline in infants fed orally.