Beta thalassaemia is an inherited condition in which the body has difficulty making haemoglobin. Patients are therefore anaemic and the unused iron-based compounds normally used to make haemoglobin are deposited elsewhere in the body.
The mild form of the disease with only one of two genes involved – so-called thalassaemia minor – is least severe. In cases of the severe form, thalassaemia major, deposits of a compound called haemosiderin can occur in the pituitary gland and in the ovary. This can cause the woman to stop her periods or never to start them in the first place. These patients are subfertile.
Patients with thalassaemia minor do not have this problem although will always be anaemic. However, you should not take iron during pregnancy.
Finally, I should say that if the partner also has thalassaemia, a child could be severely ill, so couples should seek genetic advice.