If the abortion is not clean, ultrasound will show abnormal echoes in the uterine cavity. Some pregnant women still have irregular vaginal bleeding after a medication abortion or an abortion, some in large amounts and some in small amounts, so an ultrasound must be performed to see if there are residues in the uterine cavity. It is important to hold urine during the examination to allow the bladder to fill up so that the uterine image shows clearly to see the thickness of the endometrium and whether the echogenicity is uniform. If the abortion is not clean and there are residues, the ultrasound image will show uneven echogenicity in the uterine cavity, some large and some small, irregular in shape and not very clear in the border. When there is chorionic membrane implanted in the myometrium, then the myometrium will become thin and the structure will be disturbed, and color Doppler will detect rich blood flow signal at the edge of the residue and the combination of the myometrium. In this case, the abortion should not be performed blindly, but should be performed after medication or uterine artery intervention. In conclusion, both medication and abortion are traumatic to the uterus, and ultrasound review must be performed after abortion.