Screening Tests in Pregnancy – Sickle Cell Disease & Thalassaemia
What is Sickle Cell Disease (SCD) and Thalassaemia?
Both disorders are serious genetically inherited conditions that affect the way oxygen is carried around the body. Being genetic means that if affected, the baby is born with the condition and has it for life. People with these disorders need specialist care regularly throughout their lives.
People with SCD can get sever pain, anaemia and life threatening infections. Babies with SCD can receive early help, immunisations and antibiotics.
People with Thalassaemia major tend to need blood transfusions every 3 – 5 weeks and suffer with severe anaemia.
How could my baby get these conditions?
For your baby to be affected they must have 2 faulty genes passed onto them. 1 from mum and 1 from dad. With genetic disorders such as these, you can fall into one of three groups. 2 normal genes = not affected, 1 normal gene and 1 faulty gene = a carrier (being a carrier means you can pass on the faulty gene but you are not affected with the condition) or 2 faulty genes = affected.
Therefore, for your baby to be affected both you and your partner need to be a combination of carriers or affected. When both parents are carriers the baby has a 25% chance of being affected, 25% of having 2 normal genes and 50% of becoming a carrier themselves.
The faulty gene is more common in people with family origins in Africa, The Mediterranean, The Caribbean, south and South East Asia, India, Pakistan and the Middle East.
What is the test and when will it be carried out?
It is a simple blood test that is carried out at the booking appointment with consent from you. It is best to have it at 10 weeks. All women are offered the Thalassaemia screening. SCD screening may or may not be offered depending on your maternity unit and the area it is in. You can request it.
Do I have to have it?
No, it is your choice. The baby will have newborn blood spot screening offered on day 5 postnatally. This will screen the baby for SCD.
What are the possible results?
If you are not a carrier then you will receive a normal result and return to normal maternity care.
If you are a carrier then your partner will be invited for screening. If he is not a carrier, you will likely return to normal maternity care.
If he is a carrier, then it is possible your baby could be affected by SCD or Thalassaemia. You will be invited to discuss your options with a specialist/obstetrician. This will include the option of a CVS or amniocentesis to find out if the baby is affected. If the baby is affected with a serious haemoglobin disorder you may be offered a termination. You receive full support throughout these decisions.