33 weeks preterm babies born 20 days jaundice has not receded, there may be physiological reasons, but also may be hemolytic jaundice, or infantile hepatitis syndrome and so on. 1. Physiological jaundice: physiological jaundice in preterm infants can be 3-4 weeks after birth, while the absolute value of jaundice will not be too high, there is no abdominal distension, fever and other discomforts, jaundice has not receded but reappeared, the possibility of physiological jaundice in this case is high. 2. Hemolytic jaundice: hemolytic jaundice appears earlier, and may last longer if not treated actively. 3. Infantile Hepatitis Syndrome: When preterm babies are infected by cytomegalovirus, toxoplasmosis, etc., there will be a decrease in the liver’s ability to process bilirubin, which will make it difficult for the jaundice to subside. There are many causes of jaundice in 33-week preterm babies born 20 days, such as breast milk jaundice, etc. It is recommended to improve liver function tests and other tests, and active treatment.