Sickle cell anaemia is an inherited disease of the blood, which is characterized by chronic anaemia and periodic episodes of pain. It is caused by an error (mutation) in the gene that controls haemoglobin synthesis. The mutation leads to synthesis of sickle haemoglobin (Hb S) instead of normal adult haemoglobin (Hb A) resulting in deformed (sickle-shaped) red blood cells. Two genes regulate haemoglobin synthesis. If an individual inherits copies of the defective gene from both parents, he/she will have sickle cell anaemia while individuals inheriting only one defective sickle haemoglobin gene from one parent will not have the disease, but will carry the sickle cell trait. Individuals with sickle cell trait generally have no symptoms, but they can pass the sickle haemoglobin gene on to their children. As your husband has sickle cell disease and you are normal, the child will inherit one copy of the gene and will this have sickle cell trait. By sampling the amniotic fluid or tissue taken from the placenta, doctors can tell whether a fetus has sickle cell anaemia or sickle cell trait. This test can be done as early as the first trimester of pregnancy.
Hydroxyurea increases the production of fetal haemoglobin, which decreases the number of deformed red blood cells. Therefore, it reduces the frequency of sickle cell crises. Not everyone is treated with hydrea and it is given only to patients over age 18 who have had at least three painful crises in the previous year. The ability to father a child may be affected by the drug as the developing fetus may be affected. Couples are advised to use effective contraception for upto several months after stopping the drug. You need to discuss this issue with your doctor.