Adiposity and Fat-Free Mass of Children Born with Very Low Birth Weight Do Not Differ in Children Fed Supplemental Donor Milk Compared with Those Fed Preterm Formula

Abstract

Background: Many mothers of very-low-birth-weight (VLBW) infants (<1500 g) are unable to provide sufficient breast milk, and supplemental pasteurized donor human milk (donor milk) or preterm formula is required. The composition of donor milk differs from that of mother's milk and infants fed with donor milk often exhibit slower growth during hospitalization. The long-term impact of nutrient-enriched donor milk on growth, body composition, or blood pressure is unknown.

Objective: We aimed to determine the effects of nutrient-enriched donor milk compared with preterm formula on growth, body composition, and blood pressure of children born preterm and with VLBW. Associations with in-hospital mother's milk intake were explored.

Methods: This study was a follow-up of children at 5.5-y of age who participated in a randomized controlled trial evaluating the effect of nutrient-enriched donor milk (commencing at ≥120 mL·kg-1·d-1) or preterm formula fed as a supplement when mother's milk was unavailable. The trial intervention lasted 90 d or until hospital discharge, whichever occurred first. In this follow-up investigation, differences in total body fat percentage determined by using air displacement plethysmography (primary outcome), fat-free mass, skinfold thickness, waist circumference, BMI z scores, and blood pressure] were evaluated using linear regressions.

Results: Of 316 surviving infants from the earlier trial, 158 (50%) participated in the current study (53% male). Mean ± SD birth weight and gestational age were 1013 ± 264 g and 27.9 ± 2.5 wk. The median (IQR) intervention period was 67.5 d (52.0-91.0 d). Mean ± SD age and BMI z score at follow-up were 5.7 ± 0.2 y and -0.3 ± 1.2. Supplemental nutrient-enriched donor milk, compared to preterm formula, was not associated with growth, body composition, or blood pressure. In-hospital mother's milk intake was positively associated with height z score at 5.5 y (β: 0.07; 95% CI: 0.004, 0.1; P = 0.04).

Conclusions: Supplemental nutrient-enriched donor milk and preterm formula during initial hospitalization results in comparable long-term growth and body composition in young children born VLBW. This trial was registered at clinicaltrials.gov as NCT02759809 and at isrctn.com as ISRCTN35317141.

Keywords: blood pressure; body composition; donor milk; growth; preterm formula; preterm infant; very low birth weight.