Prenatal diagnosis or
prenatal screening (note that
prenatal diagnosis and
prenatal screening refer to two different types of tests) is
testing for diseases or conditions in a
fetus or
embryo before it is born. The aim is to detect
birth defects such as
neural tube defects,
Down syndrome,
chromosome abnormalities,
genetic disorders and other conditions, such as
spina bifida,
cleft palate,
Tay Sachs disease,
sickle cell anemia,
thalassemia,
cystic fibrosis,
Muscular dystrophy, and
fragile X syndrome. Screening can also be used for
prenatal sex discernment. Common testing procedures include
amniocentesis,
ultrasonography including
nuchal translucency ultrasound, serum marker testing, or genetic screening. In some cases, the tests are administered to determine if the fetus will be
aborted, though physicians and patients also find it useful to diagnose high-risk pregnancies early so that delivery can be scheduled in a tertiary care hospital where the baby can receive appropriate care.