Down Syndrome | Diagnosis & Treatments

How is Down syndrome diagnosed?

Down syndrome can be detected during pregnancy through prenatal tests or diagnosed after birth with a chromosomal analysis called a karyotype.

Prenatal tests

Prenatal tests are optional tests that can be performed during pregnancy to identify a fetus’ sex, age, size, and placement in the uterus. Prenatal tests also detect chromosomal conditions such as Down syndrome, congenital heart defects, and other genetic conditions.

Prenatal tests and timing

Ideally, the best time to start thinking about prenatal tests is before conception. Your doctor can look at your family’s medical history to see if the parents might have an increased risk for having a child with a genetic condition such as Down syndrome. Sometimes, the doctor will recommend pre-conception testing for parents' articular conditions based on this evaluation.

Before any parent decides whether or not to get prenatal testing, it’s important to know all the options and the advantages and disadvantages of each one.

Screening tests

Screening tests determine the likelihood of Down syndrome and other medical conditions without providing a definite diagnosis.

The different types of screening tests include:

  • blood tests that measure protein and hormone levels in pregnant women. Abnormal levels, whether high or low, can indicate a genetic condition.
  • ultrasound, a non-invasive imagining technique that uses sound waves to generate an image of the fetus. An ultrasound can identify congenital heart conditions and other structural changes such as extra skin at the base of the neck that may indicate Down syndrome.

Clinicians use the combined results of blood tests and ultrasound results to estimate the chance that a fetus has Down syndrome.

Based on the results of the screening tests and the mother’s age, a clinician may recommend follow-up tests such as MaternaT21 or Panorama to look for fetal DNA in the maternal blood. These relatively new tests indicate if there is a high or low probability that a fetus has Down syndrome. These tests are not diagnostic and cannot say with absolute certainty whether or not a fetus has Down syndrome.

Diagnostic tests

Diagnostic tests can determine whether a fetus has Down syndrome with nearly 100 percent accuracy. However, because these tests require using a needle to obtain a sample from within the uterus, they carry a small increased risk of miscarriage and other complications.

Diagnostic test options include:

  • chorionic villus sampling (CVS), a prenatal diagnosis method in which a small biopsy of the placenta is taken for specific genetic testing. CVS is used to detect any condition that involves specific chromosomal abnormalities, like Down syndrome. This test is usually performed during the first trimester between 10-14 weeks of gestation.
  • amniocentesis, a prenatal diagnosis method in which a needle is inserted into the amniotic sac that surrounds the fetus. Amniocentesis is most often used to detect Down syndrome and other chromosomal abnormalities. This test is usually done in the second trimester, after 15 weeks of gestation.

Testing for related conditions

  • ultrasounds use sound waves to create an image of a fetus’ internal organs so clinicians can look for markers of Down syndrome and other possible issues like intestinal
  • echocardiograms use sound waves to create an image of the heart so doctors can look for signs of congenital heart defects
  • fetal magnetic resonance imaging (MRI) provides clinicians an image of a fetus’ internal organs, including the brain and intestines

Diagnostic testing after birth

Down syndrome can also be diagnosed after a baby is born. Clinicians can usually tell if a baby should be tested for Down syndrome based on a physical examination.

The first test, a rapid blood test (FISH), confirms the presence of extra material from chromosome 21. Results are available within a few days.

A karyotype test is a blood test that takes about one to two weeks for results. This provides further information on the type of Down syndrome, which is important in determining the chance of trisomy 21 in a future pregnancy.

How is Down syndrome treated?

While there is no cure for Down syndrome, there are a variety of treatments and therapies to address a child's unique medical issues and developmental profile.

Medical treatment

Almost half of children with Down syndrome are born with congenital heart defects. Babies with congenital heart conditions are treated by pediatric cardiologists, doctors who specialize in diagnosing and treating heart problems.

Treatment is based on the severity of the child's heart condition. Some mild heart defects don't require any treatment. Others can be treated with medications, interventional procedures, or surgery.

Depending on the child’s other medical issues, medications can treat conditions like seizure disorders, hypothyroidism, and childhood leukemia. Surgery may be necessary to treat upper neck abnormalities and stomach problems.

Physical and behavioral therapies

A variety of therapies are available to address a child's unique physical, behavioral, and communication needs and can have a significant positive impact on children’s learning and development.

Therapies include:

  • occupational therapy to improve motor skills, such as using the hands and other parts of the body, and help children deal with sensory inputs from the environment
  • physical therapy to increase mobility and muscle strength and help children to work within functional limitations
  • speech therapy to help improve communication skills and self-expression
  • behavioral therapy focused on managing emotional and behavioral problems

Educational therapy

Most of the educational therapies used to address the core symptoms of Down syndrome are provided through programs run by states and local school systems.

It’s important for parents and teachers to understand that no single educational approach is right for every child. Most children with Down syndrome can spend at least some of their time in a general education classroom with typically developing peers but some children can benefit from a smaller setting with more individual support.

  • Children under age 3 who have Down syndrome or other developmental challenges are eligible to receive developmental services through state-run, federally mandated programs. These programs have different names in each state. In Massachusetts, the program is called Early Intervention, administered by the Massachusetts Department of Public Health.
  • From age 3 to age 21, children can access educational support through their public school system.

What is the long-term outlook for children with Down syndrome?

The average life span for people with Down syndrome has increased dramatically since the early 1900s. On average, people with Down syndrome live to about 55 to 60 years of age and some live into the 70s or 80s.

With the help of specialized educational programs and support, many children with Down syndrome learn and grow successfully. An increasing number of people with Down syndrome graduate from high school. Some young people with Down syndrome take college classes and many hold jobs in the community after they finish school. Some adults with Down syndrome live independently or in community-based homes or supported living arrangements, where they can get additional support depending on their needs.