Kemp, Johanna ElizabethBecker, PietWenhold, Friedeburg Anna Maria2023-09-192023-09-192023-10Kemp, J.E., Becker, P. & Wenhold, F.A.M. High protein content in breast milk from South African mothers of preterm infants. Acta Paediatrica, International Journal of Paediatrics 2023; 112: 2129–2136. https://doi.org/10.1111/apa.16910.0803-5253 (print)1651-2227 (online)10.1111/apa.16910http://hdl.handle.net/2263/92318AIM : Macronutrient and energy content of human milk are largely assumed for fortification practices. The aim was to explore macronutrient and energy content of transition and mature human milk from South African mothers of preterm infants with a birth weight <1800 g. Secondary objectives compared day to night milk; and explored associations with selected innate factors. METHODS : In this single-centre, observational study macronutrient and energy content of day, night and mixed samples of transition (first 14 days of life) and mature (from Day 15 of life) human milk were analysed with mid-infrared spectroscopy. RESULTS : In total, 116 samples (38 days; 37 night; 41 mixed) from 47 mothers were retained for statistical analysis. Mean true protein, carbohydrate, fat and energy content of mixed samples per 100 mL were 1.5 ± 0.4 g, 7.2 ± 0.7 g, 3.5 ± 0.9 g and 69.4 ± 9.9 kcal, respectively. Mixed transition milk (n = 9) had 1.9 ± 0.3 g protein and 67.4 ± 9.6 kcal and mixed mature milk (n = 32) 1.4 ± 0.4 g protein and 70.0 ± 10.1 kcal, per 100 mL.The protein content of transition (p = 0.004) and mature (p = 0.004) milk were significantly higher than published data. Transition milk: 1.5 g protein, 65 kcal; mature milk: 1.2 g protein, 72 kcal per 100 mL. Night samples had less fat (p = 0.014) and energy (p = 0.033) than day samples. With increasing day of life protein content declined (p = 0.003). CONCLUSION : The protein content of human milk from South African mothers of preterm babies differs from published data and has implications for human milk fortification practises.en© 2023 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License.Transition milkPreterm infantMacronutrient analysisLow- and middle-income countries (LMICs)Human milkVery low birth weight (VLBW)SDG-02: Zero hungerHealth sciences articles SDG-03SDG-03: Good health and well-beingHealth sciences articles SDG-10SDG-10: Reduced inequalitiesArticle