What prenatal test is performed to detect chromosomal abnormalities?

Amniocentesis is a prenatal test that involves taking a sample of amniotic fluid, which contains fetal cells. This procedure is typically performed between the 15th and 20th weeks of pregnancy. The fetal cells obtained from the amniotic fluid can then be analyzed for chromosomal abnormalities, such as Down syndrome, as well as other genetic disorders.

This test is considered highly accurate for diagnosing chromosomal abnormalities because the analysis can directly examine the chromosomes of the fetus. In contrast, while ultrasound can detect some structural abnormalities and blood tests can screen for certain conditions or risk factors, they do not directly analyze chromosomes to the same extent as amniocentesis. Chorionic villus sampling also detects chromosomal abnormalities, but it is done earlier in the pregnancy and involves sampling tissue from the placenta rather than amniotic fluid. Each of these tests has its own specific indications, but amniocentesis is particularly focused on assessing chromosomal health in a definitive manner.