Understanding Down’s syndrome: Diagnosis and treatment

How do I know if my child has Down’s syndrome?

Although a newborn’s physical characteristics may lead doctors to suspect Down’s syndrome, a genetic test called a karyotype must be done to confirm diagnosis. A karyotype involves testing a small amount of the baby’s blood.

It is also possible to screen for and diagnose Down’s syndrome during pregnancy. A screening test estimates a woman’s risk of having a child with Down’s syndrome. A diagnostic test determines whether the foetus has Down’s syndrome.

Pregnant women are offered routine screening for Down’s syndrome between weeks 10 and 14 of pregnancy. This is usually by a combined test that measures levels of certain proteins and hormones in the blood and a detailed ultrasound scan. 

The results of these tests, together with the woman’s age, are used to predict the risk of Down’s syndrome, which becomes increasingly common as women get older. If this suggests a high risk, diagnostic tests must be done to confirm the diagnosis.  Screening may sometimes suggest a high risk when in fact Down’s syndrome is not present (a “false positive” result), and sometimes show a low risk when the foetus does have Down’s syndrome (a “false negative” result).

The prenatal tests used to diagnose Down’s syndrome are chorionic villus sampling (CVS) at 11 to 14 weeks, or amniocentesis after 15 weeks of pregnancy. These tests do carry a small risk of miscarriage because they require the insertion of a needle into the fluid surrounding the foetus or into the placenta in order to examine the baby’s chromosomes. These tests accurately diagnose Down’s syndrome 98% to 99% of the time. 

What are the treatments?

Although there is no cure for Down’s syndrome, children born with the condition can lead productive lives. Everyone born with Down’s syndrome exhibits some level of learning disability but this usually falls within the mild to moderate range. Just like other children, babies with Down’s syndrome will learn basic skills --  such as sitting, walking, talking, toilet training and bathing, but they will do so at a delayed pace. Early intervention with physiotherapy, begun shortly after birth, can help strengthen muscles for these basic motor skills.

Regular medical care to treat the chronic health problems associated with Down’s syndrome is also important. Children with Down’s syndrome should receive regular sight and hearing tests, be evaluated for thyroid problemsand receive the normal childhood immunisations.

Some adults with Down’s syndrome live with their families; some live in care homes with others with Down’s syndrome; and some live independently. Many people with Down’s syndrome have jobs. The opportunities for people with Down’s syndrome are great, and there is no reason not to expect these individuals to make lasting, positive contributions to society.

How can I prevent it?

At present, there is no way to prevent Down’s syndrome. However, scientists continue to learn more about the genetic basis of Down’s and hope that in the future it will be possible to improve, correct or prevent many of the problems associated with the condition.

There are studies suggesting that some women who have had a child with Down’s syndrome had an abnormality in the way their body processed folic acid. If confirmed, this finding provides another reason why all women who may become pregnant should take a prenatal vitamin supplement with 400 micrograms of folic acid.