Human Milk Fortifier After Neonatal Intensive Care Unit Discharge Improves Human Milk Usage Rates for Preterm Infants

A common neonatal intensive care unit (NICU) discharge feeding strategy for preterm infants with growth failure who are fed exclusively expressed human milk (EHM) has been to enrich mother's own milk with formula powder or supplement 2-3 feeds per day with formula. However, this strategy displaces human milk from the diet. Our NICU recently adopted the standard practice of adding commercial human milk fortifier (HMF) to human milk feedings after discharge.

We aimed to compare breastfeeding rates and growth using the aforementioned 2 strategies.

Preterm infants (<34 wk of gestation at birth) exclusively feeding EHM fortified with HMF at 2 weeks before discharge were included in this retrospective study. The HMF group (n = 92) continued fortifying with HMF at home, whereas the historical comparison group (n = 35) received our previous guidance to enrich or supplement using postdischarge formula.

Rates of human milk exclusivity after discharge decreased significantly less in the HMF group than those in the historical comparison group (to 83% compared with 39% at the first outpatient visit and 27% compared with 6%, respectively, at the second outpatient visit). Rates of any EHM feedings were also significantly higher in the HMF group. Fenton z-scores for weight, length, and head circumference were not significantly different between the groups.

Continuing EHM fortification with HMF after NICU discharge, rather than enriching or supplementing with postdischarge infant formula, increases rates of feeding EHM for ≥3 mo but does not affect growth.