Non-invasive DNA testing should be done for women of advanced maternal age. Senior pregnant women are pregnant women who are older than 35 years old, because over 35 years old, the quality of the eggs may be affected by the decline in physical function, then the probability of chromosomal abnormalities in the fetus will increase, so it is recommended that senior pregnant women undergo non-invasive DNA screening. Non-invasive prenatal screening, also known as non-invasive prenatal DNA testing, is based on the principle that maternal plasma contains fetal free DNA, through the collection of peripheral blood of pregnant women, using a new generation of high-throughput sequencing technology to sequence the free DNA fragments (including fetal free DNA) in maternal peripheral plasma. Through the bioinformatics analysis performed, the risk rate of fetus suffering from trisomy 21, trisomy 18, and trisomy 13 is derived, thus predicting the risk of fetus suffering from these three syndromes. Timing of the testThe test can be done from the 10th week of pregnancy and the optimal week of pregnancy is 12 to 22+6 weeks. Non-invasive prenatal DNA testing is a prenatal screening method, not a prenatal diagnostic method, and cannot replace traditional prenatal diagnostic methods. For high-risk individuals, genetic counseling and invasive prenatal diagnostic methods should be provided for a definitive diagnosis, and the clinical decision to terminate a pregnancy should not be based solely on the noninvasive results. Pregnant women should pay attention to the prenatal examination during pregnancy, actively listen to the advice of professional doctors to do a comprehensive nursing care, pay attention to rest, at the same time should relax, avoid tension, anxiety, any discomfort should be timely to the hospital, by the doctor to clarify the diagnosis, and cooperate with the doctor to deal with the symptoms.