IMPORTANCE Protein, supplied in currently available commercial fortifiers, may be inadequate to meet the requirements of very preterm infants; in addition, intraindividual and interindividual variability of human milk protein and energy content potentially contribute to unsatisfactory early postnatal growth. OBJECTIVE To determine effects on growth of different levels of enteral protein supplementation in predominantly human milk-fed preterm infants. DESIGN, SETTING, AND PARTICIPANTS This randomized clinical and partially blinded single-center trial was conducted in a neonatal tertiary referral center in Germany. Sixty preterm infants (gestation <32 weeks and weight <1500 g at birth) were recruited from October 2012 to October 2014 and included 35% of 173 eligible infants. Median (interquartile range [IQR]) gestational age at birth was 29.9 (28.7-31.2) weeks. All analyses were conducted in an intention-to-treat population. INTERVENTIONS Infants were randomly assigned to either a lower-protein (adding 1 g of bovine protein/100 mL of breast milk through a commercial human milk fortifier; n = 30) or a higherprotein group at a median (IQR) postnatal age of 7 (6-8) days. The higher-protein group (n = 30) received either standardized higher-protein supplementation (study fortifier adding 1.8 g of bovine protein/100 mL of breast milk [n = 15]) or individualized high-protein supplementation based on protein and fat content of administered breast milk (n = 15). Study interventions were continued for a median (IQR) of 41 (30-57) days and until definite discharge planning. MAIN OUTCOMES AND MEASURES Primary outcome was weight gain (g/kg/d) from birth to the end of intervention. RESULTS Sixty preterm infants (gestation <32 weeks and weight <1500 g at birth), 33 girls, were recruited from October 2012 to October 2014 and included 35% of 173 eligible infants. Median (IQR) gestational age at birth was 29.9 (28.7-31.2) weeks. Demographic characteristics and hospital courses were similar in both groups, and birth weights ranged from 580 to 1495 g in the lower-protein group and 490 to 1470 g in the higher-protein group. Weight gain was similar in the lower-and higher-protein groups: mean (95% CI), 16.3 g/kg/d (15.4-17.1 g/kg/d) in the lowerprotein group vs 16.0 g/kg/d (15.1-16.9 g/kg/d) in the higher-protein group) (P = .70), despite an increase in actual protein intake by 0.6 g/kg/d (0.4-0.7 g/kg/d) (P < .001). Head circumference and lower leg longitudinal growth were also similar, as was the proportion of cumulative total enteral feeding volume provided as breast milk: median (IQR) proportion of breast milk, 92% (79%-98%) in the lower-protein group vs 94% (62%-99%) in the higher-protein group (P = .89). CONCLUSIONS AND RELEVANCE An increase in protein intake by 0.6 g/kg/d to a mean intake of 4.3 g/kg/d did not further enhance growth of very preterm infants with a median birth weight of 1200 g, who achieved near-fetal growth rates. This might point to a ceiling effect for enteral protein intake with respect to its influence on gr...

This study was registered at www.clinicaltrials.gov. Identifier: NCT01773902.

Irrespective of the low proportions of C20:4-PC and C22:6-PC in preterm infant plasma lipids, PC is the major transporter for C20:4 and C22:6. Our data support the hypotheses that choline deficiency may impair end-organ availability of these LC-PUFA in preterm infants. Therefore, supplementation of C20:4 and C22:6 might better be accompanied by choline supplementation.

BackgroundFeeding breast milk is associated with reduced morbidity and mortality, as well as improved neurodevelopmental outcome but does not meet the high nutritional requirements of preterm infants. Both plasma and urinary urea concentrations represent amino acid oxidation and low concentrations may indicate insufficient protein supply.This study assesses the effect of different levels of enteral protein on plasma and urinary urea concentrations and determines if the urinary urea-creatinine ratio provides reliable information about the protein status of preterm infants.MethodsSixty preterm infants (birthweight < 1500 g; gestational age < 32 weeks) were enrolled in a randomized controlled trial and assigned to either a lower-protein group (median protein intake 3.7 g/kg/d) or a higher-protein group (median protein intake 4,3 g/kg/d). Half the patients in the higher-protein group received standardized supplementation with a supplement adding 1.8 g protein/100 ml milk, the other half received individual supplementation depending on the respective mother’s milk macronutrient content. Plasma urea concentration was determined in two scheduled blood samples (BS1; BS2); urinary urea and creatinine concentrations in weekly spot urine samples.ResultsThe higher-protein group showed higher plasma urea concentrations in both BS1 and BS2 and a higher urinary urea-creatinine-ratio in week 3 and 5–7 compared to the lower-protein group. In addition, a highly positive correlation between plasma urea concentrations and the urinary urea-creatinine-ratio (p < 0.0001) and between actual protein intake and plasma urea concentrations and the urinary urea-creatinine-ratio (both p < 0.0001) was shown.ConclusionsThe urinary urea-creatinine-ratio, just like plasma urea concentrations, may help to estimate actual protein supply, absorption and oxidation in preterm infants and, additionally, can be determined non-invasively. Further investigations are needed to determine reliable cut-off values of urinary urea concentrations to ensure appropriate protein intake.Trial registrationClinicaltrials.gov; NCT01773902 registered 15 January 2013, retrospectively registered.

No abstract