Tolerance of Hydrolyzed Liquid Protein Fortified Human Milk and Effect on Growth in Premature Infants

Background: We evaluated tolerance of hydrolyzed liquid protein (LP) supplement added to fortified human milk (HM) to optimize protein intake in preterm infants. Methods: A prospective observational study of 31 subjects compared with 31 historic controls, receiving mothers own milk (MOM) and/or donor milk (DM) to assess LP tolerance, growth, and risk for morbidities was conducted. Milk was analyzed for nutrient content. Feeding intolerance, defined as cessation of feedings for ≥48 hours, abdominal distension and/or residuals, necrotizing enterocolitis (NEC), and metabolic acidosis were used to assess safety, while weight and head circumference (HC) were used to evaluate growth. Results: LP added to powder-fortified HM had no impact on feeding intolerance and NEC. Biochemical parameters showed no metabolic acidosis: blood urea nitrogen levels (first week: median, 13 mg/dL; interquartile range [IQR], 9–16; last week: median, 13 mg/dL; IQR, 10.3–14; P =.94), bicarbonate levels (first week: median, 26.3 mEq/L; IQR, 24–28; last week: median, 28 mEq/L; IQR, 26.3–29.8; P =.10), and pH levels (first week: median, 7.4; IQR, 7.3–7.4; last week: median, 7.4; IQR, 7.37–7.40; P =.5). Weight and HC were not statistically significant. HM analysis showed lower protein and caloric content, respectively (MOM: 0.88 vs DM: 0.77 g/100 mL; P <.0001 and MOM: 18.68 vs DM: 17.96 kcal/oz; P =.02). Conclusions: Hydrolyzed LP is well tolerated in preterm infants with no difference in growth rates. Clinicians should focus on the need to maximize both protein and energy to optimize growth.