BackgroundAlthough breastfeeding guidelines for infants admitted to the neonatal intensive care unit (NICU) have been introduced in Japan, these guidelines have not been reflected in practice. To improve this situation, it is important for nurses and nurse-midwives to acquire knowledge of appropriate care. This study examined changes in nurse-midwives’ knowledge, attitude, and implementation of appropriate care after implementing an education program focused on early essential care for breast milk expression among mothers of preterm infants.MethodsThis pre- and post-intervention study using a single group was conducted from June 2018 to May 2019 and enrolled 36 nurse-midwives in one perinatal medical center. The education program content included nurses’ roles in early essential care for milk expression and the necessary care to promoting breast milk production among mothers of preterm infants. The nurse-midwives’ knowledge and attitude on care were investigated 3 months before (pre-1), just before (pre-2), just after (post-1), and 3 months after (post-2) the program. The nurse-midwives’ care implementation was investigated at pre-1, pre-2, and post-2. During this time, 11 mothers (before: 7, after: 4) reported the status of milk expression for 10 days after birth.ResultsThe mean knowledge scores of the nurse-midwives at post-1 and post-2 were significantly higher than that at pre-2 (post-1: p < 0.001, post-2: p < 0.001). The attitude on care scores at post-1 and post-2 were significantly higher than that at pre-2 (post-1: p < 0.001, post-2: p = 0.010). The care implementation score at post-2 was significantly higher than that at pre-2 in eight items (e.g., Q7 Explain about the effect of initiating milk expression early and assist mothers in it). However, the education program did not cause any changes in the mothers’ initiation and frequency of milk expression, and breast milk volume after birth.ConclusionsThe significant increases in the knowledge, attitude on care, and care implementation scores of the nurse-midwives suggest the beneficial effects of the education program. The small number of mothers in the survey on the practice of breast milk expression limited the full determination of the benefits of the education program for nurse-midwives.