Beyond bronchopulmonary dysplasia: impact of human milk feeding on long-term respiratory morbidity in very preterm infants.

Very preterm infants are at increased risk of respiratory morbidity, with bronchopulmonary dysplasia (BPD) being one of the most common neonatal respiratory complications. Although human milk feeding has been linked to improved respiratory outcomes in preterm infants, evidence on long-term morbidity and differences between pasteurized donor human milk (PDM) and mother's own milk (MOM) is limited. The objectives of this study are to evaluate the association between human milk exposure and long-term respiratory morbidity in very preterm infants up to 18 months and to assess whether respiratory outcomes and BPD differ according to the predominant type of human milk received during hospitalization. This prospective cohort study included infants born at < 32 weeks of gestational age and followed until 18 months. Respiratory hospital admissions and emergency department (ED) visits for respiratory causes were recorded. Infants were classified according to feeding type at hospital discharge (human milk [exclusive or mixed] vs. exclusive formula), according to the predominant type of human milk received during hospitalization (> 50% PDM vs. > 50% MOM), and according to BPD status (no BPD/1 vs. BPD 2-3). All infants received exclusively human milk during hospitalization (MOM and/or PDM); formula, when used, was introduced only shortly before discharge. Multivariable analyses were adjusted for gestational age and BPD. Among 338 infants with complete follow-up, human milk feeding at hospital discharge was associated with a lower risk of respiratory hospital admissions during the first 18 months compared with exclusive formula feeding (15% vs. 25%; p = 0.03). This association remained significant after adjustment for BPD (OR 0.55, 95% CI 0.31-0.99). No significant differences in respiratory hospital admissions were observed between infants predominantly fed PDM and those predominantly fed MOM during hospitalization (19.9% vs. 17.4%; p = 0.55). The incidence of grade 2-3 BPD did not differ according to the predominant type of human milk received during hospitalization (48% PDM vs. 51% MOM; p = 0.66) nor according to feeding type at discharge (40% exclusive formula vs. 32% human milk; p = 0.21). Infants with grade 2-3 BPD experienced significantly higher respiratory morbidity during follow-up, including respiratory hospital admissions (33% vs. 15%; p < 0.01) and ED visits for bronchiolitis or bronchospasm (60% vs. 36%; p < 0.01).

conclusionHuman milk feeding at hospital discharge was associated with a lower risk of respiratory hospital admissions during the first 18 months in very preterm infants. No differences in respiratory morbidity or incidence of grade 2-3 BPD were observed according to the predominant type of human milk received during hospitalization. Infants who developed grade 2-3 BPD experienced substantially higher respiratory morbidity during follow-up. WHAT IS KNOWN: • Very preterm infants who develop bronchopulmonary dysplasia have increased respiratory morbidity during infancy. • Human milk feeding has been associated with improved outcomes in preterm infants; however, evidence regarding respiratory morbidity beyond discharge is less consistent. WHAT IS NEW: • This study found that human milk feeding at hospital discharge was associated with fewer respiratory hospital admissions during the first 18 months in very preterm infants. • In a center using non-pooled preterm donor human milk matched to gestational age and lactation stage, no differences in post-discharge respiratory morbidity or BPD incidence were observed according to the predominant type of human milk received during hospitalization.