causes of enlarged spleen in 8 months baby can be hemolytic disease like Thalassemia, G6PD deficiency, malarial infection, leukaemia. it depends on how match the size of spleen is enlarged. In leukaemia and Thalassemia the size of spleen is quite big. In malaria infection and G6PD deficiency the size of spleen is not so much. Spleen size can also be increased in intrauterine infection like torch infection. you should do blood test like complete blood count with peripheral smear, iron studies, haemoglobin electrophoresis, torch test. This test will help in confirming the diagnosis. For the management will depend on the cause of disease. Take care.