Prenatal screening examines for aneuploid chromosome abnormalities, neural tube malformations, and screening for fetal structural malformations. Prenatal screening is a simple, feasible and non-invasive test that examines pregnant women in general and identifies suspected groups of people whose children are at high risk of developing hereditary diseases. The results of prenatal screening can be used as a reference. A positive result only means a high risk of the disease, and further confirmatory tests are needed to determine the final result, and the decision to terminate a pregnancy cannot be made on the basis of the results of the screening, which are mainly based on ultrasound, serologic screening, and non-invasive DNA (deoxyribonucleic acid) testing. Ultrasound screening can detect fetal structural abnormalities such as anencephaly, severe brain enlargement, and severe open spina bifida. Serologic screening screens for risk of Down syndrome, trisomy 18, and open neural tube defects. Non-invasive DNA screening assesses the risk of a fetus carrying common chromosomal aneuploidy abnormalities.