Background: Neonatal jaundice is a condition that is accompanied by hyperbilirubinemia. Almost all newborns (60% term and 80% preterm) have more than 5mg/dl of bilirubin during the first week of life, and approximately 6% of term infants may have levels exceeding 15 mg/dl (Young Infants Clinical Signs Study Group, 2008). It is one of the most common causes of morbidity during the first week of life. High serum bilirubin level leads to serious consequences and neurologic disorders in some of the infants with jaundice. 5-10% of these newborns have clinically important neonatal jaundice that requires treatment and care to prevent neurotoxicity and reduce serum bilirubin level (Madan, Mac Mohan, Stevenson, 2005). Recent studies in the literature have shown that there is a strong relationship between hyperbilirubinemia and breastfeeding (Garg, 2018; Flaherman 2017). In a study, it was indicated that breastfed infants had lower bilirubin levels on postnatal day 3 compared to infants fed with infant formula. The problem of jaundice that increases due to insufficient intake of breast milk/breastfeeding is usually underestimated, an exaggerated physiological jaundice treatment is often administered (symptomatically phototherapy), and breastfeeding problems are neglected (Stark, Bhutani 2016). Therefore, while the infant and the mother try to adapt to each other for successful breastfeeding, the treatment process increases breastfeeding difficulties and failure during the first postnatal week. The role and counseling of the infant's nurse are of great importance in breastfeeding of the newborn and the education of the family in neonatal jaundice. The first postnatal hours and days are the most critical times for ensuring the success of breastfeeding. Jaundice due to breastfeeding failure requires focused efforts for a program structured with breastfeeding education and special breastfeeding support. This support causes the role of nurses to become even more important.

Method: This is a randomized controlled experimental study. The data of the study will be collected from primiparous mothers who had normal delivery in the Gynecology and Obstetrics Department in Sakarya Maternity and Children's Hospital Campus affiliated to the Ministry of Health Sakarya University Training and Research Hospital between 01.08.2020-01.01.2021 and their infants until January 2021. The sample of the study was calculated in accordance with the intervention group selection criteria and by performing power analysis. Power analysis was performed using G\*Power (v3.1.7) program in order to determine sample size. The effect range value was taken as 0.70 as the method used in cases where it is unknown how many units difference is significant between the groups. In cases where Type 1 error probability (α) was 0.05 (at a confidence level of 95%), at a power level of 80% and the effect range was 0.70, the study was planned with a total of 68 mothers, including 34 mothers women for each group. The mothers to be allocated to the study and control groups will be ensured to have similarity in terms of three factors (age, educational status, gender of the infants). The individuals will be allocated into groups by simple random sampling. The sample of the study will be randomly allocated into two groups: the intervention group will be supported for breastfeeding and the feeding of infants' with breast milk, and the other group, which was the control group, will be followed in routine care of the service. Single-blind (researchers are not blind) randomization will be provided since the mothers will be provided with support for breastfeeding and the feeding of infants' with breast milk by the researchers. The statistician was also blinded for the data analysis purpose. With regard to data collection tools, the "Mother Introductory Information Form" including socio-demographic characteristics of the family, the "Newborn Introductory Information Form" including characteristic features of the infants, the "Infant Nutrition Follow-up Form" for the follow-up of breast milk milked after breastfeeding, and the "Jaundice Follow-up Form" including the follow-up of infants who are hospitalized due to jaundice before/after discharge will be used. Mothers in the experimental group will be provided with breastfeeding support, and if required, the mother's both breasts will be milked by hand and the resulting breast milk will be collected in a container. After milking, the milk will be given to the infant with the help of a teaspoon. This practice will be shown to the mother and will be performed after each feeding during the hospital stay. Mothers will be told to perform this practice at home until the infant sucks effectively and strongly, and families will be called by phone daily. No intervention will be made to the control group. Bilirubin measurements of both groups will be performed with a transcutaneous bilirubin meter both before discharge from the hospital and at the end of week 1, and the values will be recorded. At the same time, the conditions of rehospitalization due to jaundice at the end of week 1 will be recorded. In the evaluation of data, statistical analyses will be performed using the SPSS package program. The Kolmogorov-Smirnov (K-S) test will be used for normality. In order to determine whether there is a difference in the dependent variables compared to independent variables, the independent group t-test will be used if the distribution is normal in independent variables with two options, and Mann Whitney-U test will be used if distribution is not normal. The results will be evaluated at a confidence level of 95% and at a level of significance of p\<0.05.