Comparing necrotizing enterocolitis risk among extremely preterm infants by use of human-milk or bovine-milk-based fortifier

Objective: To determine the incidence of necrotizing enterocolitis (NEC) among extremely premature infants (EPI: gestational age <28 weeks) fed a base exclusive human milk diet (EHMD) as a function of human-milk fortifier (human milk-based: HM-HMF or bovine milk-based: BM-HMF). Study design: Retrospective cohort of 703 EPI, 355 at Wolfson Children’s Hospital fed an EHMD with BM-HMF and 348 at UF Health Hospital fed an EHMD with HM-HMF fortification under similar feeding protocols. The outcomes of interest were NEC ≥ stage II, surgical NEC, and mortality. Results: Baseline characteristics were similar between the groups. NEC occurred in 9.5% of HM-HMF and 6.5% of BM-HMF fortified EPI [adjusted OR: 1.48 (0.83–2.63); p = 0.18]. Similarly, no differences were found in rates of surgical NEC or mortality or age at NEC onset. Conclusion: In this large retrospective study in EPI, we did not detect any signal that fortification with HM-HMF reduced NEC incidence compared with BM-HMF supplementation.