Abstract

Introduction and aims: Human breast milk is a natural pain reliever that contains endorphins. The aim of this study was to compare the effects of breast milk and powdered milk on pain severity after a muscular injection in 1-day-old neonates. Materials and methods: One hundred neonates admitted to a teaching hospital in 11am city, Iran, participated in a randomized clinical trial in 2016. One-day-old neonates were divided into four equal groups including: the control group (no feeding); the breastfed group; the bottle-fed mother's milk group and the powdered formula group. All infants received the hepatitis B vaccine by muscle injection in the same position of the thigh. The severity and duration of pain were compared among all groups during and after injection using the DAN scoring method (evaluation behavioral scale of acute pain in newborn infant). Results: One hundred neonates (57 boys) participated in this study. The mean +/- SD age and weight for participants were 39.15 +/- 0.05 weeks and 3016 +/- 28g, respectively. Crying duration either during or after the injection in breastfed infants was significantly shorter compared to the control and powdered formula groups (9.2 +/- 3.9 and 16 +/- 4.6 s vs. 38.2 +/- 8.9 and 30.0 +/- 4.4 s, respectively, during injection, P < 0.003); (11.8 +/- 3.4 and 20.6 +/- 5.1 s vs. 56.2 +/- 6.5 and 49.8 +/- 9.6 s, respectively, after injection, P < 0.006). There was also a significant relationship between behavioral variations and pain during injection (P < 0.0001). Conclusions: The results of this study showed that breastfeeding decreases pain severity during painful experiences in neonates, which is in accordance with other reports. Based on this finding, neonates are advised to be breastfed if a painful intervention such as vaccination is needed. The pain-relieving effect of breast milk could also be added to its other suitable effects. (C) 2018 Elsevier Masson SAS. All rights reserved.