There are fetal heart, fetal buds, the main reasons for fetal arrest are embryonic factors, maternal factors and father’s reasons. 1. Embryonic factors: when the ultrasound suggests that the embryo already has fetal heart and buds, but the occurrence of fetal arrest, most of them are due to chromosomal abnormalities caused by the embryo itself, commonly caused by chromosome number and structural abnormalities, such as trisomy 18, trisomy 21, chromosomal balanced translocation, and so on. 2. Maternal factors: when the mother has a combination of systemic diseases, such as thrombophilia, hypothyroidism, diabetes mellitus, poor glycemic control, etc. or a combination of immune diseases, such as antiphospholipid syndrome, systemic lupus erythematosus, etc., is also a common cause of fetal failure. 3. Father: when the father sperm chromosomal abnormalities, such as microdeletions or duplications, chromosome number abnormalities, etc., will also increase the chance of fetal arrest.