Association between type of feeding at hospital discharge and nutritional status of Brazilian very preterm infants: a multicenter study.

Objectives: To examine trends over time in diet and size of very preterm infants, and associations of diet with size at hospital discharge/transfer.

Methods: The authors studied 4062 surviving very preterm infants born < 32 weeks' gestational age and < 1500 g between January 2012 and December 2020 from 12 Brazilian Neonatal Intensive Care Units. Diet type at discharge/transfer was classified as exclusive human milk, exclusive formula, or mixed. Outcomes were weight and head circumference at hospital discharge and the change in each from birth to discharge. The authors used linear regression to estimate adjusted associations of diet type with infant size, overall, and stratified by fetal growth category (small vs. appropriate for gestational age). The authors also examined trends in diet and infant size at discharge over the years.

Results: Infants' mean gestational age at birth was 29.3 weeks, and the mean birth weight was 1136 g. Diet at discharge/transfer was exclusive human milk for 22 %, mixed for 62 %, and exclusive formula for 16 %. Infant size in weight and head circumference were substantially below the growth chart reference for all diets. Infants fed human milk and mixed diets were lighter and had smaller heads at discharge/transfer than infants fed formula only (weight z: -2.0, -1.8, and -1.5; head z: -1.3, -1.2 and -1.1 for exclusive human milk, mixed and exclusive formula respectively).

Conclusion: Results suggest high human milk use but gaps in nutrient delivery among hospitalized Brazilian very preterm infants, with little evidence of improvement over time.