Chromosomal abnormalities may cause spontaneous abortion, but a few do not. Chromosomal abnormalities, including numerical and structural abnormalities, can lead to poor embryo quality, which results in the natural elimination of the fetus and is the main factor leading to spontaneous abortion. However, some chromosomal abnormalities are also born, causing malformations in newborns, such as congenital stupidity in trisomy 21-trisomy. Chromosomal abnormalities usually result in spontaneous abortion or fetal abruption at an early age. Therefore, it is important for pregnant women to undergo regular checkups during pregnancy, such as NT, non-invasive DNA testing, ultrasound, fetal heart ultrasound, etc. These are all means used to screen for embryonic abnormalities, and early detection will allow for early intervention. Amniocentesis is also commonly recommended for pregnant women over 35 years of age.