Prenatal Testing: In many countries, pregnant women are offered tests to determine if their baby has Down syndrome. In Barbados, most cases are diagnosed at birth. Prenatal tests can be categorized as screening or diagnostic. Screening tests estimate the chance of Down syndrome, while diagnostic tests, such as amniocentesis and chorionic villus sampling (CVS), can confirm the diagnosis with almost 100% accuracy.

Newborn Testing: Down syndrome is typically diagnosed at birth based on physical traits such as low muscle tone, a single crease across the palm, and a slightly flattened facial profile. A chromosomal analysis called a karyotype is then done to confirm the diagnosis.