As with any test, there are benefits and risks of having a blood spot test. It’s important you’re aware of these before you accept a screening invitation.
The benefits of having the blood spot test include:
- one test screens for 9 conditions – all from just a few drops of blood taken from your baby’s heel
- some tests can prevent disability and save your baby’s life
- earlier treatment may improve health outcomes
There are no associated risks with having the blood spot test. However, by not having the test there's a risk your baby could become seriously ill if these conditions aren't identified and treated.
Sickle cell disease
Sickle cell disease is passed from parents to children through altered haemoglobin genes. Haemoglobin's the part of the blood that carries oxygen around the body. The blood cells change to a ‘sickle’ (or hook) shape and get stuck in the small blood vessels. This can cause pain and damage to the baby or serious infection. In some cases, it causes death.
1 in every 2,500 babies born in the UK has the condition.
If your baby has sickle cell disease that isn’t detected, they would develop pain. They could suffer serious infection and damage to their body. This could be improved or even avoided with early screening and the right treatment.
Read more about sickle cell disease
Cystic fibrosis affects many parts of the body. For your baby, this means that the lungs and the pancreas are most affected. This leads to regular chest infections and problems digesting food and absorbing the nutrients they need.
1 in every 2,500 babies born in Scotland has the condition.
Cystic fibrosis occurs when a baby inherits an altered gene from each parent. You need to have both genes to have the condition. Both parents carry only one altered gene, so are unaffected. 1 in 25 people in Scotland is a cystic fibrosis carrier.
If your baby has cystic fibrosis that isn’t detected, there may be a delay in diagnosis. This means that your baby might develop problems that early treatment could help reduce or avoid.
Read more about cystic fibrosis
Babies with congenital hypothyroidism don’t produce enough of the hormone thyroxine. This is needed for healthy mental and physical development.
Congenital hypothyroidism is rare. It affects about 1 in every 3,500 babies born in Scotland.
A baby with untreated congenital hypothyroidism would grow at a slower rate than other babies. They might also have severe learning difficulties and may die.
Inherited metabolic disorders
Inherited metabolic disorders mean certain substances in food can’t be broken down in your baby’s body.
The blood sample will test for whether your baby has any of the following 6 inherited metabolic disorders:
- phenylketonuria (PKU)
- medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
- maple syrup urine disease
- isovaleric acidaemia (IVA)
- glutaric aciduria type 1 (GA1 )
- homocystinuria (HCU)
These disorders all carry a very high risk of delayed development and irreversible learning disabilities. These can be severe if they’re not detected early.
Some of these disorders can also cause life-threatening illness, even coma under certain circumstances, and they can be associated with other medical problems. Without treatment, babies can become suddenly and seriously ill.
Breaking down fat
Babies with MCADD deficiencies may have issues breaking down fat to make energy under certain circumstances.
Build up of amino acids
Babies born with 5 of the 6 disorders find it harder to break down certain amino acids. Amino acids are fundamental parts of all foods except pure fat and sugar. When babies drink milk their body breaks the protein down into amino acids. Most of these are used to make new body proteins.
Any leftover amino acids have to be broken down further and used for energy or removed as waste. For babies with inherited metabolic disorders, some leftover amino acids can build up in their blood and other organs, such as their brain. This can cause serious issues.