Chromosomal examination is commonly used for screening for abnormalities. Chromosome tests are performed to check whether the number and shape of chromosomes are normal. These chromosome tests are used to determine which genetic disorders and genetic mutations can occur. Usually, chromosome tests are performed by drawing blood from the arm, observing the chromosomes with the help of high-tech equipment, and then comparing them with normal chromosomes to find chromosomal problems, and then deducing the cause of the disease based on the chromosomal abnormalities that cause the disease. The chromosome test can also be used to test the baby, using the amniotic fluid of the pregnant woman to determine whether the child has a congenital disease after observation, so that the pregnant woman can avoid giving birth to a child with a problem. The human body has a certain number of chromosomes, and if there are chromosomes that are missing or different from the normal chromosomes, they can cause some diseases. These diseases have no cure until now, but can only be solved by relieving the symptoms. Chromosome tests are used to check the genes and find the cause of the disease so that children with congenital diseases can be prevented. It is also possible to find the cause of the disease.