Enteral nutrition with unfortified human milk during the first 2 postnatal weeks often leads to cumulative protein and energy deficits among preterm infants. Fortified human milk administered soon after birth could increase fat-free mass (FFM) and improve growth in these infants.
This was a masked, randomized trial. Starting on feeding day 2, extremely preterm infants 28 weeks or younger fed maternal or donor milk were randomized to receive either a diet fortified with a human-based product (intervention group) or a standard, unfortified diet (control group). This practice continued until the feeding day when a standard bovine-based fortifier was ordered. Caregivers were masked. The primary outcome was FFM-for-age z score at 36 weeks of postmenstrual age (PMA).
A total of 150 infants were randomized between 2020 and 2022. The mean birth weight was 795±250 g, and the median gestational age was 26 weeks. Eleven infants died during the observation period. The primary outcome was assessed in 105 infants (70%). FFM-for-age z scores did not differ between groups. Length gain velocities from birth to 36 weeks PMA were higher in the intervention group. Declines in head circumference-for-age z score from birth to 36 weeks’ PMA were less pronounced in the intervention group.
In infants born extremely preterm, human milk diets fortified soon after birth do not increase FFM accretion at 36 weeks’ PMA, but they may increase length gain velocity and reduce declines in head circumference-for-age z scores from birth to 36 weeks’ PMA.