Higher-Volume Breastmilk to Improve Growth among Preterm Infants in Zambia: A Randomized Clinical Trial

• Postnatal malnutrition, wasting, and stunting are common among preterm infants in low- and middle-income countries. • Higher-volume breastmilk production was feasible in this randomized trial. • Higher-volume breastmilk feeding did not improve growth velocity in very preterm infants. • Mid-arm circumference at 40 weeks’ postmenstrual age was improved with higher-volume breastmilk feeding. To test the hypothesis that among very preterm infants, higher-volume feeding versus usual-volume feeding with exclusive breastmilk improves growth at 40-weeks’ postmenstrual age (PMA). We conducted a randomized controlled trial among preterm infants 28 0/7 to 31 6/7 weeks’ gestation or weighing 1000-1999g at birth admitted to the Kangaroo Mother Care Ward at the Women and Newborn Hospital, Lusaka, Zambia between June 2022 and February 2023. Study participants were randomized with a 1:1 parallel allocation to usual-volume breastmilk (140-180 ml/kg/day) or higher-volume breastmilk (200-240 ml/kg/day) achieved with additional breastmilk expression. Daily measurements of feeding volume were recorded until discharge. Following hospital discharge, study participants were assessed at 40-weeks’ postmenstrual age for weight, length, mid-arm circumference, and head circumference. The primary outcome was growth velocity from enrolment to 40-weeks’ postmenstrual age. 190 preterm infants were enrolled. The mean±standard deviation (SD) number of days from enrollment to discharge was 9±4 days. Recorded breastmilk volumes during hospitalization differed between groups (239±47 mL/kg/day in higher-volume versus 189±84 mL/kg/day in usual-volume; p< 0.001). There was no difference in growth velocity to 40 weeks’ PMA between groups (mean±SD, higher-volume 14.1±4.8 g/kg/day versus usual-volume 14.6±5.4 g/kg/day; p=0.51). The mid-arm circumference increased in the higher-volume group (10.9±1.3 cm versus 10.5±1.1 cm; p=0.04) but other growth parameters did not differ at 40-weeks’ postmenstrual age. Adverse outcomes did not differ. Higher-volume exclusive breastmilk feeding with breastmilk expression is feasible but did not improve growth velocity at 40-weeks’ postmenstrual age in very preterm infants.