Clinically, the incidence of spontaneous abortion is 15%-25%, and more than 80% of them are early abortions that occur before 12 weeks of pregnancy. The patients with 2 or more miscarriages accounted for about 5% of women during the childbearing period, and about 1% of women with 3 or more abortions. The risk of recurrent miscarriage increases with the increase in the number of miscarriages. The embryo loss rate of patients with a history of more than 3 consecutive miscarriages after re-pregnancy is close to 40% (according to the expert consensus in the diagnosis and treatment of recurrent miscarriage). Relevant studies have shown that embryonic chromosomal abnormalities such as chromosome deletion, duplication, and aneuploidy are the primary factors leading to abnormal fetal development, malformations, stillbirth, and fetal abortion.