The effect of fortified breast milk on weight gain in preterm infants admitted in the NICU at Arusha, Tanzania.

Abstract

Background: Breast milk is recommended as the ideal nutrition support for enteral feedings of preterm infants. However, it does not meet all preterm nutritional requirements. Developed countries have demonstrated the effectiveness of fortification of breast milk for preterm infants in order to meet the necessary growth demands for protein and energy. The use of a standardized feeding guideline with fortification of breast milk for preterm infants has not been reported nor widely adopted in Tanzanian hospitals. Objectives: This study aimed to assess the effect of fortified breast milk on weight gain in preterm infants admitted in the Neonatal Intensive Care Unit at Arusha Lutheran Medical Center, Arusha, Tanzania, Methods: In this retrospective cohort study, we included 116 preterm infants with gestational age between 26 weeks and 36 weeks and 6 days admitted in the NICU between 01January 2013 and 31 December 2017. The files were grouped into fortified and non-fortified breast milk. Preterm, maternal and feeding factors were collected using a checklist. Comparison of mean weight gain difference and length of hospital stay between the two groups were done using student’s t test. Linear regression was used to adjust for the confounders, and propensity score matching was used to reduce the effect of selection bias. Kaplan Meier survival function curves were constructed to compare the time to regain birth weight between the two groups, then cox proportional hazards was conducted. Feeding related complications were determined using Chi square and Fisher exact test at a 5% level of significance. Outcome measures: The primary outcome was weight gain in grams/kilogram/day. Length of hospital stay, time to regain birth weight and feeding-related complications were secondary outcomes. Results: The average gestational age in both groups was 32 weeks, both groups had more males with more extreme preterm infants (6.9%) in the fortified breast milk group. Mothers in the fortified breast milk group were older. Most preterm infants in the fortified breast milk group started feeds within 24 hours of birth. Fortified breast milk resulted in a higher mean weight gain 11.9±3.7 g/kg/day compared to the 7.5±3.6g/kg/day in the non-fortified breast milk group (p<0.001). However preterm infants who received fortified breast milk stayed in the hospital 12 days longer compared to those on non-fortified breast milk (p=0.001). Time to regain birth weight xii was 14 days for both groups. Among preterm infants who received fortified breast milk, 7 (12%) experienced vomiting and 1(1.7%) had an abdominal distension. None were diagnosed with necrotizing enterocolitis (NEC). Conclusions and recommendations: Fortified breast milk remains to be an important intervention to support the extra uterine development of preterm infants. Extremely preterm infants should be prioritized to fortification rather than very/late preterm infants. Adjustable fortification could be effective and practical in reaching adequate protein intakes and growth.