With each Pregnancy for an at risk couple, there is a:
- 1 in 4 chance that the child will not be a carrier at all.
- 1 in 4 chance that the child will carry beta thalassaemia trait. This does not cause any health problems.
- 1 in 4 chance that the child will carry sickle cell trait (AS). This will not cause any health problems.
- 1 in 4 chance that the child will inherit beta thalassaemia from one parent and sickle cell haemoglobin from the other. Such a child will have haemoglobin S/beta thalassaemia.
In short, in each pregnancy there is a 3 out of 4 chance of a healthy child, and a 1 in 4 chance of a child with haemoglobin S/beta thalassaemia.
Haemoglobin S/beta thalassaemia
This is a form of sickle cell disorder. People with sickle cell usually have anaemia, an increased risk of serious infections, and attacks of severe pains in joints or elsewhere from time to time. They need to take antibiotics daily and attend a sickle cell clinic several times a year. They sometimes need admission to hospital, for treatment.
It's possible to try to predict whether a couple could have children with milder, moderate or severe haemoglobin S/beta thalassaemia. However, as yet predictions are rather unreliable.