Amniocentesis is generally required for older pregnant women over 35 weeks of age. Pregnant women with a family history of Down syndrome or abnormalities on ultrasound and other tests are advised to undergo the test under the guidance of a physician. Amniocentesis is commonly used in the clinic for genetic diseases, inherited metabolic diseases, intrauterine infections and fetal lung maturity, but not all pregnant women need to do this test, generally for pregnant women over 35 years of age must do amniocentesis. Pregnant women with a family history of Down’s syndrome, or those with a high chance of maternal blood Down’s syndrome, or those whose ultrasound and other tests show abnormalities (e.g., abnormal nuchal translucency bands, fetal malformations) are recommended to have it done under the guidance of a physician. Amniocentesis is a method of prenatal diagnosis that carries certain risks, and is usually done during the 16th to 24th week of pregnancy. For the above groups of pregnant women, it is recommended that they go to a regular medical institution for amniocentesis in a timely manner.