BackgroundThe feeding behavior of newborns is influenced by the conditions of both the mother and newborn before and after birth. AimsThis study aimed to investigate the factors associated with newborn feeding behavior, focusing on skin-to-skin contact (SSC) as a promoting factor and epidural analgesia as an inhibiting factor, using the Japanese version of the Infant Breastfeeding Assessment Tool (IBFAT). Study DesignProspective observational study conducted in Japan. ParticipantsA total of 176 pairs of healthy mothers and their healthy full-term newborns. Outcome MeasuresThe primary outcome was newborn feeding behaviors measured using the Japanese version of IBFAT within about one day of birth. Stepwise multiple regression analysis was performed to explore the relationship between IBFAT scores and variables that might influence newborn feeding behavior. ResultsMultiple regression analysis revealed that lower IBFAT scores were associated with a higher dose of epidural fentanyl (β = −0.40), and higher IBFAT scores were associated with a longer duration of SSC (β = 0.26), even after adjusting for gestational weeks and Apgar scores. The dose and duration of synthetic oxytocin administration were not associated with IBFAT scores in the multivariate analysis. ConclusionsOur study showed a dose-dependent relationship between fentanyl and SSC, suggesting that consistently implementing SSC for the maximum duration possible may enhance newborn feeding behaviors, which are reduced by fentanyl administration.