Donor human milk storage and gastrointestinal morbidities in preterm infants: A case-control study.

Background: Prolonged storage of donor human milk may alter its bioactive components, potentially affecting preterm infant outcomes. No prior studies have examined the impact of donor human milk storage duration on necrotizing enterocolitis or spontaneous intestinal perforation.

Methods: In a retrospective case-control study (February 2022 to January 2024) at a single neonatal intensive care unit, we evaluated preterm infants (<32 weeks' gestational age or birth weight <1700 g) receiving donor human milk. Cases (n = 36) had necrotizing enterocolitis (Bell stage ≥2A) or spontaneous intestinal perforation; controls (n = 226) were disease free. Donor human milk storage duration (days from expression to consumption) was calculated using lot expiration dates. Logistic regression assessed associations, adjusting for gestational age, birth weight, and other confounders.

Results: Of 262 infants, 36 developed necrotizing enterocolitis (n = 28) or spontaneous intestinal perforation (n = 8). Mean donor human milk storage duration was 258.6 (SD, 29.9) days in cases and 244.5 (SD, 21.7) days in controls (P = 0.01). Each additional storage day increased the adjusted odds of necrotizing enterocolitis or spontaneous intestinal perforation by 3.6% (95% confidence interval, 1.17-5.5; P < 0.001), after accounting for maternal and infant comorbidities.

Conclusions: Prolonged donor human milk storage is associated with necrotizing enterocolitis and spontaneous intestinal perforation in preterm infants, particularly those <750 g. These findings suggest a need to reevaluate donor human milk storage guidelines for high-risk neonates, pending multicenter validation.