The effect of inhaling mother’s breast milk odor on the behavioral responses to pain caused by hepatitis B vaccine in preterm infants: a randomized clinical trial

Abstract

Background: Non-pharmacologic pain relief in preterm infant is an important measure. Familiar odors for neonates have soothing effects in some researches. The aim of this study was to compare the effect of maternal breast milk odor (MBMO) with that of another mother’s breast milk odor (BMO) on the behavioral responses to pain caused by hepatitis B (HB) vaccine injection in preterm infants.Methods: This single-blind randomized clinical trial was performed in the neonatal intensive care unit of Babol Rouhani Hospital, Iran from February 2019 to March 2020. Ninety preterm infants who must to be receive the HB vaccine, were randomly assigned into three groups of MBMO (A), another mother’s BMO (B) and control with distilled water(C). Oxygen saturation(SaO2), blood pressure(BP) and heart rate(HR) were recorded by electronic monitoring and premature infant pain profile (PIPP) were determined through video recording in tree groups during intervention. The chi-square, ANOVA and ANCOVA were used for analyzing data, and P<0.05 was considered significant.Results: No significant differences were seen between tree groups in mean± SD of HR, BP, Sao2 before intervention, (P>0.05). After intervention, the mean heart rate in group A, B and C was 146. 6±14.3, 153.70±17.5 and 155.70±17.7 respectively, (P=0.01). There was no significant difference between groups in the mean of SaO2, systolic and diastolic blood pressure after intervention (P>0.05). The mean PIPP score in groups A, B and C was 6.6±1.3, 10 ±2 and 11.4±1.9 respectively, (P<0.001).Conclusions: Stimulation with MBMO is effective in reducing the pain of preterm infants, so it can be used in less invasive procedures such as needling.Trial registration: IRCT, IRCT20190220042771N1. Registered 18 May 2019- Retrospectively registered, https://en.irct.ir/trial/37646