Beta thalassaemia carrier and pregnancy

If a woman is identified to be a carrier of Beta Thalassaemia then they should be referred for genetic counselling. This should be prior to conception.

• as well as finding out if their partner is also a carrier of beta thalassaemia, it is important to find out if he/she is a carrier of another interacting haemoglobin such as sickle haemoglobin (Hb S), Hb O Arab or Hb Lepore - this can be achieved via a haemoglobinopathy screen
  • if a partner is positive as a carrier for beta thalassaemia, there will be a 1 in 4 chance (25%) that any child they have will inherit beta thalassaemia from both parents - this will mean that the child will have Beta Thalassaemia major with the development of severe anaemia and other associated medical problems (note that the child is not anaemic at birth but becomes very anaemic by about 8 months of age)
  • if a child inherits beta thalassaemia from one parent and Hb E, Hb O Arab or Hb Lepore from the other parent, then the child will have a type of thalassaemia. If this happens the child may develop medical problems associated with beta thalassaemia intermedia or beta thalassaemia major
  • if a child inherits beta thalassaemia from one parent and sickle cell from the other parent, then the child will have a type of sickle cell disease called "sickle beta thalassaemia" - in this situation the child may develop medical problems associated with sickle haemoglobin
• during pregnancy a woman who is a carrier of beta thalassaemia may become anaemic - in this instance it is important to identify whether this is related to her being a carrier of beta thalassaemia or because of iron deficiency (with its associated low ferritin)
• pregnancy in a woman who is a carrier for beta thalassaemia should be managed with specialist advice