Preterm Infants: Human Milk Linked to Fewer Respiratory Admissions

For parents of premature infants, every breath their baby takes is a source of both hope and anxiety. New research offers a reassuring signal: human milk feeding at hospital discharge is linked to fewer respiratory hospital admissions during the first 18 months of life for extremely preterm babies, compared to exclusive formula feeding. The findings, published earlier this month, add to a growing body of evidence supporting the protective benefits of human milk for vulnerable newborns.

The Study: Tracking Long-Term Respiratory Health

The research, a prospective cohort study published in the European Journal of Pediatrics and also highlighted by Medscape News UK, followed 338 infants born before 32 weeks of gestation. Researchers recorded respiratory hospital admissions and emergency department visits for respiratory causes up to 18 months after birth. Infants were categorized based on their feeding type at discharge – either human milk (exclusive or mixed) or exclusive formula – and the predominant type of human milk received during hospitalization (pasteurized donor human milk or mother’s own milk). The study found that 15% of infants fed human milk at hospital discharge experienced a respiratory hospital admission during the follow-up period, compared to 25% of those exclusively formula-fed (p = 0.03). This association remained significant even after accounting for bronchopulmonary dysplasia (BPD), a chronic lung condition common in preterm infants.

It’s key to note that all infants in the study initially received exclusively human milk – either mother’s own milk or pasteurized donor milk – during their hospital stay. Formula was only introduced shortly before discharge, if at all. This detail underscores the importance of initiating human milk feeding as early as possible in preterm infants.

Defining Bronchopulmonary Dysplasia and Respiratory Morbidity

BPD, or bronchopulmonary dysplasia, is a serious lung disease that develops in some babies born prematurely. It occurs when the lungs are damaged after prolonged use of a ventilator and/or oxygen therapy. The severity of BPD is graded from 1 to 3, with higher grades indicating more severe lung damage. Respiratory morbidity encompasses a broader range of respiratory issues, including infections like bronchiolitis and pneumonia, as well as wheezing and other breathing difficulties. The study specifically looked at the incidence of grade 2-3 BPD, but found no significant differences based on the type of human milk received during hospitalization.

What Does This Mean for Preterm Infants?

The study’s findings suggest that continuing human milk feeding after hospital discharge can provide ongoing respiratory protection for very preterm infants. Whereas the exact mechanisms behind this protective effect are not fully understood, human milk contains a complex array of bioactive components – including antibodies, immune cells, and growth factors – that are known to support immune development and lung maturation. These components may help to reduce the risk of respiratory infections and inflammation, ultimately leading to fewer hospital admissions.

Still, it’s crucial to understand that this study demonstrates an association, not causation. While human milk feeding was linked to fewer respiratory admissions, it doesn’t definitively prove that human milk *caused* the reduction. Other factors, such as socioeconomic status, access to healthcare, and parental smoking habits, could also play a role. The researchers adjusted for gestational age and BPD in their analysis, but other potential confounding factors may remain.

Donor Milk vs. Mother’s Own Milk: No Observed Difference

Interestingly, the study found no differences in respiratory outcomes or the incidence of grade 2-3 BPD based on whether infants received predominantly pasteurized donor human milk (PDM) or mother’s own milk (MOM) during hospitalization. What we have is reassuring news for families where mothers are unable to provide a sufficient supply of their own milk. Pasteurized donor milk, obtained from screened and processed milk donations, offers a safe and effective alternative. You can find more information about donor milk banks through organizations like the Human Milk Banking Association of North America.

Contextualizing the Risk: A Closer Look at the Numbers

The observed difference in respiratory hospital admission rates – 15% in the human milk group versus 25% in the formula group – represents a relative risk reduction of approximately 40%. However, it’s important to consider the absolute risk reduction. This means that for every 100 preterm infants discharged on human milk, approximately 10 fewer respiratory hospital admissions would be expected during the first 18 months, compared to those discharged on exclusive formula. While statistically significant, this difference highlights the need for a comprehensive approach to respiratory care for preterm infants, encompassing not only feeding practices but also proactive monitoring and timely intervention.

The Ongoing Process of Refining Guidance

Current guidelines from organizations like the World Health Organization (WHO) and national health authorities strongly recommend human milk feeding for preterm infants whenever possible. These recommendations are based on a wealth of evidence demonstrating the numerous benefits of human milk, including improved neurodevelopmental outcomes, reduced risk of necrotizing enterocolitis (a serious intestinal condition), and enhanced immune function. The findings from this recent study are likely to further reinforce these recommendations and may inform future guidance on optimal feeding practices for preterm infants.

What Comes Next: Surveillance and Further Research

Researchers are continuing to investigate the long-term effects of human milk feeding on respiratory health in preterm infants. Ongoing studies are exploring the specific bioactive components in human milk that contribute to respiratory protection, as well as the optimal duration and composition of human milk feeding. Hospital surveillance systems are also being used to monitor respiratory outcomes in preterm infants and identify potential risk factors. These efforts will help to refine our understanding of the complex interplay between nutrition, lung development, and respiratory health in this vulnerable population.