Thalassaemia is a blood disorder that involves a reduced production of haemoglobin genes. This condition is genetically passed on when both parents have the disorder or are carriers.

There are two types of thalassaemia:

Alpha (ɑ-thalassaemia)

  • Alpha-globin gene deletion.
  • Severity ranges from mild to severe.

Beta (ꞵ-thalassaemia)

  • Beta-globin gene mutations
  • One mutation = mild signs and symptoms – thalassaemia minor.
  • Two mutations = moderate to severe signs and symptoms – thalassaemia major.


Thalassaemia is the most common form of hereditary anaemia:

  • ɑ-thalassaemia mainly affects individuals from Southeast Asia and Africa – 12-50%.
  • ꞵ-thalassaemia is more prevalent among those in the Mediterranean – 1-20%.
  • Due to migration, numbers of ꞵ-thalassaemia are increasing in Western and Northern Europe, Northeast Asia and North America.

Data from the British Society of Haematology (2024).

  • Globally each year, there are more than 70,000 babies born with thalassaemia syndromes.
  • There are over 100 million people who are carriers of asymptomatic thalassaemia.

Signs and symptoms

There are various signs and symptoms of thalassaemia, depending on whether you have alpha or beta; which generally include:

  • Feeling tired, weak or dizzy.
  • Shortness of breath.
  • Pale or yellow skin.
  • Dark urine.
  • Swollen stomach.
  • Slight deformity of facial bones.


If thalassaemia is left untreated there is the possibility of health complications:

  • An increased risk of blood infections.
  • Heart failure or liver damage due to elevated levels of iron in the blood which may occur from frequent blood transfusions.
  • Enlarged spleen.
  • Bone deformities or osteoporosis.


Treatment is determined by the severity of the disorder.

Blood transfusions may be required with severe cases requiring this every 3-4 weeks.


Women with thalassaemia may have a reduced ability to become pregnant, mainly associated with moderate or serious types of the disorder. There is also a chance thalassaemia can produce an elevated likelihood of health risks during pregnancy. Also, any challenges confronting pregnant women due to iron overload and anaemia will be similar which ever form of thalassaemia.

Pregnant women with non-transfusion-dependent thalassaemia (NTDT) will have mild to moderate levels of anaemia, which can present a significant issue during pregnancy. The gravity of anaemia has also shown to possibly affect maternal health and foetal growth.

There is increasing evidence which supports the multidisciplinary management of pregnancy in thalassaemia syndromes. The British Society for Haematology Guideline for the management of conception and pregnancy in thalassaemia syndromes recommend monthly reviews for at least 28 weeks of gestation followed by fortnightly checks.

Testing for thalassaemia can be performed prior to birth to determine the severity of the disorder via:

  • Chorionic villus sampling – commonly carried out near the 11th week of pregnancy.
  • Amniocentesis – normally undertaken at the 16th week of pregnancy.

After birth, children with moderate to severe thalassaemia can present with signs and symptoms by the age of two.