Prischa Oktavia Pengarang Eni Monaliska Sihombing STr.Keb, M.Kes Dosen Pembimbing 1 Ermita Silvana Simanungkalit, S.Tr.Keb.MKM Penguji 1

Breast Milk (BM) is a fluid secreted by a mother's breast glands, providing natural and highly nutritious food with high energy, which is produced starting from pregnancy. Breast Milk should ideally be given to a child for at least 6 months, and breastfeeding should continue until the child is 6 months old. Factors that affect the smooth production of BM include breast care. Breast care is a conscious and regular activity to maintain breast health. Prolactin influences the quantity of BM production, while oxytocin affects the process of milk ejection. This research aims to evaluate the relationship between postnatal mothers' knowledge of breast care and the efficiency of breastmilk secretion at the Nurhalmah Clinic in the Percut Sei Tuan Subdistrict in 2023. The research method used is an analytic survey design with a cross-sectional approach. Data were collected from 30 respondents. Univariate analysis results showed that the majority of mothers had sufficient knowledge (53.4%) and experienced poor breastmilk secretion efficiency (70.0%). Bivariate analysis revealed a significant relationship between postnatal mothers' knowledge of breast care and breastmilk secretion efficiency (p = 0.003). This result indicates that postnatal mothers' knowledge of breast care contributes to breastmilk secretion efficiency. Therefore, enhancing postnatal mothers' knowledge of breast care can be a crucial factor in improving breastmilk secretion efficiency. This research provides valuable insights into the importance of education and support related to breast care for postnatal mothers to enhance breastmilk secretion efficiency. These efforts can help improve the well-being of both mothers and infants during the postnatal period. The conclusion of this research is that there is a significant relationship between the postnatal mothers' knowledge of breast care and the smoothness of breast milk secretion at the Nurhalmah Clinic in the Percut Sei Tuan Subdistrict with a p-value of 0.003. Keywords: Knowledge, Breast, Breast Milk (BM)