A platelet count of 468 x 10^9/L in an 8-day-old infant is abnormal and on the high side, because the normal range of platelets in newborns is similar to that of adults, which is (100~300) x 10^9/L. There are many reasons that lead to thrombocytosis in newborns, and the following are common: 1. Reactive thrombocytosis: Infants with relatively low immunity after birth are prone to acute inflammation or iron deficiency anemia and platelet elevation. This situation usually does not need special treatment, as long as the elimination of inflammation, and regularly go to the hospital for review. 2. It may be due to insufficient body fluids, insufficient water intake or insufficient milk, the blood in the body is concentrated resulting in elevated platelets, need to be more hydrated. 3. Infection: If the newborn is infected with bacteria, viruses and other pathogenic bacteria, invading into the body leading to blood clotting dysfunction, platelet count is high. 4. Primary thrombocythemia, platelet count will also be elevated. For newborns with elevated platelet counts, it is recommended to go to the pediatrics department of the hospital for further examination, and after identifying the cause, treatment should be carried out under the guidance of the doctor to promote the return of platelet counts to normal.