Thalassemia is an autosomal recessive blood disorder, also known as “thalassemia”. Because it is a genetic disease, blood supplements or transfusions can only treat the symptoms, but not the root cause. What should a pregnant woman with thalassemia do? There are two common types of thalassemia in pregnant women, type A (alpha) and type B (beta). Thalassemia is an autosomal recessive blood disorder, also known as “thalassemia”. Because it is a genetic disease, blood supplements or transfusions can only treat the symptoms, but not the root cause. The rate of thalassemia A is quite high, about 3 to 4 out of 100 people have the gene for this disease, but it may not always develop. The proportion of carriers of thalassemia type B is lower, with about 1 in 100 people in Taiwan carrying the genetic gene. Chances and management of thalassemia in pregnant women In general, if only one partner in a couple has the gene for thalassemia, the fetus will not have serious or fatal consequences. However, if both partners carry the recessive gene, there is a 1/4 chance that the fetus may get severe or fatal anemia, a 1/2 chance of carrying the gene like both parents but not fatal or with serious health consequences, and a 1/4 chance that the pregnant woman may be completely normal. Therefore, nowadays, during the first prenatal check-up, the physician will order a hematocrit, hematocrit and mean cell volume (MCV) to screen for the presence of thalassemia. If the MCV is below 80, both spouses must be tested at the same time. In the unfortunate case of a couple with the same type of thalassemia, the pregnant woman must undergo a chorionic villus test or amniocentesis or fetal cord blood sampling to analyze the fetus’ genes. Severity of thalassemia major in pregnant women Pregnant women with confirmed thalassemia major in the fetus are advised to terminate the pregnancy by abortion. This is because the child may die in the womb, or it may develop hydrops fetalis at the end of the pregnancy and die soon after birth, and even if it survives, it may require long-term blood transfusion or bone marrow transplant. On the other hand, if the test results show that the fetus is genetically normal or has a mild form of thalassemia, the pregnancy can be continued with peace of mind.