Non-invasive DNA prenatal testing, also known as non-invasive prenatal DNA testing, non-invasive fetal chromosome aneuploidy testing, etc. According to the American College of Obstetricians and Gynecologists Committee, an international authoritative academic organization, Non-invasivePrenatalTesting is the most widely used name for the technology. Non-invasive DNA prenatal testing requires only venous blood from the pregnant woman, and uses next-generation DNA sequencing technology to sequence free DNA fragments (including fetal free DNA) from the mother’s peripheral plasma, and the sequencing results are analyzed for bioinformatics, from which fetal genetic information can be obtained to detect the presence of the three major chromosomal disorders in the fetus. Amniocentesis, also known as “amniocentesis”, is one of the prenatal testing procedures. It is performed by taking a specimen of amniotic fluid from a pregnant woman to obtain information about the health and development of the fetus. Amniocentesis has been widely used for prenatal diagnosis for more than 40 years, and prenatal diagnosis through amniocentesis has become an integral part of modern obstetrics, and is currently the most commonly used prenatal diagnosis technique in China. The purpose of amniocentesis: amniotic fluid cells are cells shed from the fetus and have the same genetic information. Testing of amniotic fluid obtained by amniocentesis can be used for the assessment of intrauterine conditions of the fetus and the diagnosis of fetal diseases. 1.Diagnosis of fetal congenital diseases The culture of amniotic fluid cells or the extraction of amniotic fluid cell DNA can be used for genetic diagnosis, such as for the diagnosis of fetal chromosomal diseases and monogenic diseases. 2.Diagnosis of fetal metabolic diseases For some metabolic diseases that cannot be diagnosed through genetic diagnosis, intrauterine diagnosis can be made by measuring the concentration of relevant enzymes in amniotic fluid. 3.Fetal neural tube defects The determination of methemoglobin and acetylcholinesterase in amniotic fluid can be used for the diagnosis of open fetal neural tube abnormalities (mainly including: anencephaly and spina bifida). 4.Determination of fetal lung maturity Determination of the ratio of lecithin/sphingomyelin in amniotic fluid can help to determine whether the fetal lung is mature and help to make a choice on the timing of termination of pregnancy. 5.Diagnosis of amniotic cavity infection Culture of amniotic fluid or determination of inflammatory factors can help diagnose the presence or absence of amniotic cavity infection.