Alpha-thalassemia and Pregnancy

The difference between alpha-thalassemia and beta thalassemia

The two conditions differ in several respects. However, the most important of these is that in alpha-thalassemia (á-thalassemia), the problem is that of missing (rather than defective) genes.

Also a different set of genes is affected (alpha, rather than beta). What these sets of genes have in common is that they are both to do with production of components of the blood pigment hemoglobin.

Prevalence of alpha-thalassemia

Alpha-thalassemia is found throughout the world. However, its highest concentration is in South-East Asia and, to a lesser extent, the Indian sub-continent.

Sub-types of alpha-thalassemia

There are several sub-types of alpha-thalassemia but we shall concentrate on the main types. Suffice it to mention here that alpha-thalassemia major (where all four alpha genes are missing) is fatal. Affected babies are born very sick and survive for a few hours at most.

Being an alpha-thalassemia carrier

There are several sub-groups of Thalassemia carriers, a situation that makes this considerably more complex to describe than beta-thalassemia.

There are four alpha genes. The true carriers are those who have one or two missing alpha genes. That state is called alpha-thalassemia trait.

The carriers are clinically healthy and lead normal independent lives. Pregnancy may be the first time their compromised oxygen-carrying capacity is put under strain.

Missing 3 ‘alpha’ genes out of the four

Those patients who have three missing alpha genes tend to have chronic anemia. This is brought about by constant destruction of the red cells in the body, the so-called hemolytic anemia. This type of anemia is not exclusive to people with alpha-thalassemia.

Such patients are said to have HbH disease.

Special measures for pregnancy in individuals with the alpha-thalassemia trait

Special measures are seldom required. Their anemia can be treated with oral iron supplements and folic acid. If severe, blood transfusion is given but not injectable iron.