You can't. Sickle cell anemia is an inherited genetic disorder. If one parent has sickle cell disease (scd), and the other does not, all children will be carriers of sickle cell trait. If one parent has scd and the other has sickle cell trait, there is a 50% chance that any child will have scd. If both parents have sickle cell trait, there is a 25% chance that any child will have scd.
Sickle cell . If family planning and you and/or your partner have sickle cell disease or trait it is advisable to meet with a genetic counselor. You can do preimplantation genetic testing to assure not having a child with sickle cell disease though this can be expensive. If the child has sickle trait, then there are generally no major problems and the child can be expected to be otherwise normal.