Screening during pregnancy: Sickle cell and thalassaemia disorders

What are sickle cell and thalassaemia disorders?

Sickle cell and thalassaemia disorders are types of Heamoglobin disorders and they affect the haemoglobin in the blood. People with certain types of sickle cell disorder:

  • can experience attacks of very severe pain
  • may have serious, life-threatening infections
  • are usually anaemic
  • will need medicines and injections when they are children, and throughout the rest of their lives, to stop them from getting infections.

How do we screen for sickle cell and thalassaemia disorders?

Sickle cell and thalassaemia are screened for through the Family Origin Questionnaire. This gives details of maternal and paternal family origins, and determines whether there is a higher risk of the baby inheriting sickle cell or thalassaemia disorders. Where a higher risk is identified a blood test is offered.

 

How are sickle cell and thalassaemia disorders passed on?

Sickle cell and thalassaemia disorders are passed on through genes. People are only usually affected if they inherit two or more of the affected haemoglobin genes – one from their mother and one from their father. People who inherit just one unusual gene are known as ‘carriers’. It’s important to understand that carriers are healthy and do not have the disorder. However, if a carrier has a baby with someone else who is also a carrier, or who has one of the disorders, there is a chance that their baby could have the disorder.

Carriers are more likely if the parents or grandparents come from countries with malaria, or where malaria was common in the past. For example Poland, the Mediterranean, Africa, the Caribbean, the Middle East, India, Pakistan, South America, or South and South-East Asia.

Diagnosing sickle cell and thalassaemia disorders or a sickle cell carrier early in pregnancy gives more time for a care plan to be developed to allow the best support to be given to mother and child.

Sickle cell carriers can experience some rare problems in situations when their bodies might not get enough oxygen (for example, when having an anaesthetic). People who are thalassaemia carriers do not experience these problems.

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