Weight gain in hospitalised low birth weight (LBW) premature infants receiving breast milk or breast milk with human milk fortifier in the Nelson Mandela Bay Health District

Abstract

Rationale: Worldwide, hospitals with premature units have one generalised objective, i.e. to achieve postnatal growth and body composition similar to that of a normal foetus of similar gestational age. Optimal nutrition leads to optimal neurodevelopment and breastfeeding (BF) is known as the golden standard for infant nutrition. Human breast milk (BM) has significant value for preterm and term infants and is of special benefit to HIV infected mothers. Maternal supplementation is provided as part of the standard protocol in certain hospitals in the Eastern Cape province to those mothers who breastfeed their low birth weight (LBW) infants after delivery. human milk fortifier (HMF) is a nutritional supplement that is added to expressed breast milk for feeding preterm infants in order to meet their high energy and protein needs and therefore supporting the recommended growth velocity of 10g/kg/day-15g/kg/day. Some hospitals within South Africa provide HMF to preterm infants as part of their standard nutritional protocol in order for the infant to gain weight if BM only failed to produce adequate results. To date, little to no South African studies support or discourage the use of HMF for LBW infants. This study aimed to describe the effect of maternal supplementation compared with breast milk with HMF, or a combination of maternal supplementation and breast milk with HMF, on growth velocity in hospitalised LBW premature infants within the Nelson Mandela Bay health district. The proposed study design followed a longitudinal, observational, descriptive study in a cohort of LBW infants. The study was analytical using quantitative empirical data. Study participants were selected, by using convenience sampling, at Dora Nginza Hospital, Zwide between October 2015 and August 2016 (ethics approval: EC_2016RP27_564). Quantitative data on anthropometric measurements was collected from study participants. Primary care givers provided written informed consent. Registered nurses were trained and performed anthropometrical measurements according to standardised methods. A structured questionnaire was completed by the principal reasarcher as a source of data collection. Numerical data was described using means and standard deviations. Chi squares were used to describe the associations between maternal risk factors and birth weight outcomes. ANOVA was used to determine the relationship between growth velocity and the various supplementation groups. A sample size of 91 LBW preterm infants and mother pairs were entered into this study. The majority of mothers, 64% (n=58) fell in the age category of 20-35 years old. Of the total maternal sample (n=88), 35% (n=31) were classified in the at risk age category, i.e. 36years old. Out of the total infant sample (n=91), 65% (n=59) was classified as VLBW, 22% was LBW and 22% (n=20) was ELBW. No statistically significant association was found between infant growth velocity and maternal risk factors. The group receiving BM with HMF had a mean growth velocity of 19.75 g/kg/day (SD=6.45) that was statistically significantly (p<0.05) more than the other groups. The maternal supplementation only group and the maternal supplementation and BM fortification group showed mean growth velocities of 12.26 g/kg/day (SD=5.41) and 12.29 g/kg/day (SD=6.97) respectively. A post hoc test was done between growth velocity in the supplementated groups and the length of hospital stay. These results reveal that the group receiving BM with HMF had a significantly (p<0.05) shorter mean length of hospital stay of 11.29 days (SD=7.02), compared with the group on the combination of maternal supplementation and BM with HMF. In this study, infants receiving HMF with BM showed the highest growth velocity with the shortest hospital stay before discharge. In this group, infants were already receiving an adequate BM intake of 150-180 ml/kg/day prior to participation in the study. This meant that the HMF group consisted of more stable preterm infants compared to the rest of the supplementated groups. However, a large proportion of participants in the maternal supplementation group also showed adequate to good growth velocity. The researcher recommends the implementation of maternal supplementation only, as standard of care for all hospitalised lactating women. Furthermore, timeous addition of HMF to expressed BM is necessary for infants with growth velocities <15 g/kg/day. This may save costs to the hospital as the use of HMF allowed for better weight gain and earlier discharge