Early feeding of fortified breast milk and in - hospital - growth in very 1 premature infants : a retrospective cohort analysis

32 Background and aim: Fortified human milk may not meet all nutritional needs of very 33 preterm infants. Early transition from complementary parenteral nutrition to full enteral feeds 34 might further impair in-hospital growth. We aimed to investigate the impact of the cumulative 35 intake of fortified human milk on early postnatal growth in a cohort of very low birth weight 36 infants after early transition to full enteral feeds. 37 Methods: Retrospective single-centre observational study. Data are presented as median 38 (interquartile range). 39 Results: N=206 very preterm infants were analysed (gestational age at birth 27.6 (25.6-29.6) 40 weeks, birth weight 915 (668-1170) g). Full enteral feeds were established at postnatal day 8 (641 10) and adequate postnatal growth was achieved (difference in standard deviation score for 42 weight from birth to discharge -0.105(-0.603-0.323)). Standard deviation score for weight from 43 birth to day 28 decreased more in infants with a cumulative human milk intake >75% of all 44 enteral feeds (-0.64(-1.08-0.34)) compared to those with <25% human milk intake (-0.41(-0.745 0.17); p=0.017). At discharge, a trend towards poorer weight gain with higher proportions of 46 human milk intake persisted. In contrast, we observed no significant difference for head 47 circumference growth. 48 Conclusions: Our current standardized fortification of human milk may not adequately 49 support early postnatal growth. 50 51