OBJECTIVE: This study investigated possible influences of medical interventions during labor on maternal blood pressure during a breastfeed 2 days postpartum. SUBJECTS AND METHODS: Sixty-six primiparae with normal deliveries were consecutively recruited. Blood pressure was measured at -5, 10, 30, and 60 minutes during a morning breastfeed 2 days postpartum. Five treatment groups were formed based on the medical interventions received during labor: Non-medicated mothers (Control group, n=21); mothers receiving epidural analgesia (EDA) with oxytocin (OT) stimulation (EDA(OT) group, n=14); mothers receiving EDA without OT stimulation (EDA(non-OT) group, n=7); mothers receiving OT stimulation only (OT intravenously [iv] group, n=9); and mothers receiving 10 IU of OT intramuscularly (im) only (OT im group, n=15). RESULTS: Baseline diastolic, but not systolic, blood pressure differed between the groups as displayed by significantly lower diastolic blood pressure in the EDA(non-OT) group compared with the Control group, the OT iv group, and the EDA(OT) group (p=0.045, p=0.041, and p=0.024, respectively). Both systolic and diastolic blood pressure fell significantly during the breastfeeding session in the Control group (p=0.001 and p=0.004, respectively), the OT im group (p=0.006 and p=0.001, respectively), and the EDA(OT) group (p=0.028 and p=0.002, respectively), and the fall in diastolic blood pressure tended to be significant in the OT iv group (p=0.050). The duration of skin-to-skin contact before breastfeeding correlated positively with the decrease in systolic blood pressure in the OT im group (R(s)=0.540, p=0.046). CONCLUSION: Administration of EDA during labor lowers baseline diastolic blood pressure and abolishes the fall in blood pressure in response to a breastfeed 2 days after birth.