The absence of naked eye abnormalities in amniocentesis means that the results of amniocentesis examination, identified by chromosomal images after cell culture, do not show significant abnormalities, indicating that diseases with abnormal fetal chromosome numbers can be excluded. However, genetic disorders as well as metabolic disorders and neural tube malformations cannot be excluded. Amniocentesis is a common method of prenatal diagnosis, and the optimal time to extract amniotic fluid by puncture is between the 16th and 24th weeks of gestation. Chromosome cultures are used to determine the presence of chromosomes in the baby, but amniocentesis does not completely rule out structural abnormalities in the fetus, such as congenital heart disease. At this time, it is necessary to combine it with a screening test (ultrasound) at 23-26 weeks to see if the fetus has any structural malformations. In addition, amniocentesis is recommended during pregnancy for the presence of fetal chromosomal disorders in pregnant women over 35 years of age, those who have delivered abnormal fetuses in the past, and those who have had Down’s syndrome screening or non-invasive DNA during pregnancy indicating high risk.