Risk Factors. The risk factors for getting sickle cell anemia is having two parents who have the mutated hemoglobin beta gene. The risk for two people with sickle cell trait having a child with sickle cell anemia is 25 percent for each pregnancy. The risk of having a child who is a carrier is 50 percent for each pregnancy, while the chances of a child who does not receive a mutated gene from either parent is 25 percent for each pregnancy. But again, with this disease the child of one parent who has a mutated gene other than the hemoglobin beta gene and a parent with sickle cell trait can still have medical issues.