Blood transfusion is indicated in the following condition with sickle cell anaemia

Indications of Blood transfusion in Sickle Cell Anemia Frequent sickling episodes Twin pregnancy Poor obstetrical outcome Severe anaemia Blood transfusion replaces the abnormal cells with normal red cells The objective of transfusion is to keep the hematocrit value above 25% and concentration of Hb–Sunder 50%  Prophylactic transfusions during pregnancy remain controversial