The percentage of underlying disorders in the group of pneumonia was 66.7%, and the group of septicemia 77.7%, including hyaline membrane disease, bronchopulmonary dysplasia, gastroesophageal reflux, congenital rubella syndrome, b thalassemia, congenital diaphragmatic hernia, acute myeloid leukemia, myeloid aplasia, Down syndrome, jejunal atrophy, cerebral sequelae.