Jaundice in newborns that has not subsided in one month may be caused by breast milk jaundice, hemolytic disease of the newborn, biliary atresia and so on. 1. Breast milk jaundice: it mainly occurs in newborns who are exclusively or predominantly breastfed, which will easily lead to a significant increase in the level of jaundice, and the jaundice will gradually return to normal after stopping breastfeeding. 2. Hemolytic disease of the newborn: it is often caused by immune hemolytic disease due to the incompatibility of mother and child’s blood type, which will lead to jaundice in newborns, accompanied by anemia, hepatosplenomegaly and other symptoms. 3. Biliary atresia: it may be caused by intrauterine or postnatal viral infection, which is a kind of bile duct occlusive disease, and will lead to jaundice in newborns, with deepening of urine color and white clay-colored stools. Newborn jaundice for a month has not subsided, there may be other causes, you should take the newborn to the hospital in a timely manner to identify the cause of targeted treatment.