The thalassemias are a group of genetic blood diseases that cause a reduction of the production of normal hemoglobin in the red blood cells. Hemoglobin is a protein carried by the red blood cells, which brings oxygen to all the parts of the body. The reduction of hemoglobin in the blood results in anemia.
There are two types of thalassemia, alpha thalassemia and beta thalassemia, depending on which protein chain of the hemoglobin molecule is missing in the red blood cells. Thalassemia is also categorized into three groups, depending on its severity: thalassemia major is the most severe form, thalassemia intermedia is a less severe form, and thalassemia minor may cause no symptoms at all.
Children with thalassemia are usually normal at birth but soon develop symptoms of paleness, headaches, fatigue, shortness of breath, jaundice, and enlargement of the spleen. They may not want to eat and they may vomit frequently after feedings. Thalassemia is treated with certain drugs and, in some cases, regular blood transfusions.
The thalassemias are especially common in areas where there are high rates of malaria, such as southeast Asia, China, the Mediterranean, and Africa. Women and their partners who want to become pregnant and who come from these areas should undergo testing to determine whether they carry the thalassemia trait. If both parents carry the trait, there is a considerable risk that the baby will develop thalassemia, and they may want to seek genetic counselling to determine what their options are.
Thalassemia in pregnancy
Women with thalassemia who require blood transfusions often have a higher rate of infertility. However, some women with the disease are able to become pregnant. If you have thalassemia and you are thinking of becoming pregnant, there are a number of important health considerations for you and your unborn baby.
Considerations for the baby’s health
If you have thalassemia and your partner carries the trait for thalassemia, there is a chance that your baby may inherit the disease. A genetic counsellor can explain the risks to you and your partner, and offer you testing options to determine if the unborn baby has been affected.
Considerations for the mother’s health
The stress of pregnancy can make the symptoms of thalassemia worse. The woman’s heart and liver are most vulnerable during pregnancy, as is the endocrine system, which secretes hormones in the body. Each of these systems must be closely monitored before and throughout pregnancy.
During pregnancy, the volume of blood in the mother’s body rises substantially. This can lead to anemia, which can increase the need for blood transfusion, and makes the heart work that much harder to push blood to all the body’s tissues. The higher volume of blood in the mother’s body also adds to the amount of work that the heart has to do. Therefore, women with thalassemia need to have their heart function checked before they become pregnant. During pregnancy, they may need to have regular blood transfusions to lessen the amount of stress on the heart.
People with thalassemia have an increased risk of developing type 1 diabetes. The stress of pregnancy can worsen this condition. Diabetes needs to be well controlled before and throughout pregnancy.
Folic acid is an important nutritional requirement through the early weeks of normal pregnancy, and the same is true for women with thalassemia. In addition to helping to prevent neural tube defects in the developing baby, folic acid will help to reduce the mother’s risk of developing a special type of anemia called megaloblastic anemia. Other nutrients and supplements may be needed as determined by your doctor.
For more information, see "Thalassemia" in our Health A-Z.