After abortion, hcg can’t go down, it may be caused by placenta retention, re-pregnancy, tumor and so on, which can be treated by surgery, reabortion and other methods. 1. Placental retention: it is the more common reason why hcg can’t go down, this situation can be diagnosed through gynecological ultrasound. If it is clear that there is a residue in the uterine cavity, the uterus must be cleared, and when the placenta is completely out of the hcg will fall. 2. Re-pregnancy: after the drug abortion hcg has not come down, it may be in the abortion after sex, within one month after the abortion, pregnant again, can be determined by ultrasound, if this time and rediscovered the gestational sac, considering that the abortion after sex lead to another pregnancy, you have to do abortion again. 3. Tumor: After abortion, hcg has not been able to come down, or once dropped and rose again. It may also be trophoblastic tumor. If this is the case, generally need surgical treatment. So if a woman has a medical abortion 20 days hcg can not go down, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor, improve the relevant examination, to clarify the cause of the disease, symptomatic treatment.