The Effects of Breastfeeding and Breast Milk Taste or Smell on Mitigating Painful Procedures in Newborns: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Newborns hospitalized in the neonatal intensive care unit are exposed to an average of 10 painful procedures per day. The pain-related experiences of babies can be associated with neurodevelopmental disorders that may affect them throughout their lives.Aim/Objective: The purpose of this study was to summarize and analyze the analgesic effects of breastfeeding alone, expressed breast milk, and breast milk smell on newborns and present stronger evidence that would guide clinical practice and future studies.Methods: We searched articles published between 2000 and 2021 on the CINAHL, Cochrane Central, Web of Science, PubMed, Scopus, Science Direct, Eric, and OVID databases. Nine full texts that met the inclusion criteria (Population: Newborn term or preterm babies, Intervention: Implementing breastfeeding, expressed breast milk, breast milk taste, or breast milk smell alone or in combinations in the intervention groups, Comparison: Making comparisons to the standard care of the clinic where the study was conducted, Outcomes: Including at least one pain-related criterion, Study design: Randomized-controlled trials) were included in this systematic review and meta-analysis. The nine randomized controlled studies in total that were included in this study were carried out between 2004 and 2021 with 33-130 newborns in their samples. The total number of newborns was 720. The effects of these interventions on pain scale scores, heart rate, and oxygen saturation were also analyzed.Results: According to the results of this systematic review and meta-analysis, the breastfeeding, breast milk smell, or breast milk taste interventions had large effect sizes in terms of pain management during and after the procedures. These interventions had medium effect sizes in terms of heart rate during the procedures and large effect sizes after the procedures. In terms of oxygen saturation, they had large effect sizes during the procedures and medium effect sizes after the procedures.Conclusion: Breastfeeding and breast milk interventions are significantly effective nonpharmacological alternatives for painful procedures.