Effects of human milk on short-term outcomes of very/extremely low birth weight preterm infants

Objective To study the effects of human milk on feeding intolerance, infant growth and development, complications during hospitalization and length of hospital stay in very/extremely low birth weight (VLBW/ELBW) preterm infants. Methods VLBW/ELBW preterm infants admitted to the Division of Neonatology, Children's Medical Center of the Second Xiangya Hospital from May 2015 to April 2018 were enrolled in this retrospective study and were assigned into two groups: human milk group (human milk accounted for at least 50% of total enteral feeding during hospitalization) and formula group (exclusive formula feeding due to breastfeeding contraindication or insufficient human milk supply). Feeding intolerance, neonatal growth, complications and length of hospital stay were compared between the two groups using independent sample t-test, Mann-Whitney U test and Chi-square test (or Fisher's exact probability test). Results A total of 113 VLBW/ELBW infants were enrolled consisting of 52 in the human milk group and 61 in the formula group. The starting time of enteral feeding, duration of minimal enteral feeding and incidence of feeding intolerance were similar between the two groups (all P>0.05). The increasing rate of milk volume was (8.4±1.6) ml/(kg·d) in the human milk group and (7.6±1.4) ml/(kg·d) in the formula group (t=2.853, P 0.05). The incidence of neonatal necrotizing enterocolitis (NEC) in the human milk group was lower than that of the formula group [1.9% (1/52) vs 11.5% (7/61), χ2=3.894, P 0.05). There were 14 cases (26.9%) of BPD in the human milk group, of which eight were mild and six moderate. While in the formula group, 24 cases (39.3%) had BPD and among them, four, 18 and two infants were mild, moderate and severe BPD, respectively. BPD cases in the human milk group were less severe than those in the formula group (U=-2.645, P<0.05). The length of hospital stay of the human milk group was shorter than that of the formula group [(47.5±14.8) vs (53.9±16.3) d, t=-2.129, P<0.05)]. Conclusions Human milk for VLBW/ELBW infants may shorten the time to full enteral feeding and the length of hospital stay, reduce the incidence of NEC, decrease the severity of BPD. VLBW/ELBW infants fed with fortified human milk have similar growth rate as those fed with formula milk. Key words: Breast feeding; Infant, very low birth weight; Infant, extremely low birth weight; Infant, premature; Prognosis