After the abortion surgery, HCG should return to the non-pregnant state, that is, within the reference range, but each hospital has different instruments to test the HCG value, the reference range is also different, for example, most hospitals have a normal reference range of 0-5U/L. After the abortion surgery, the HCG value of the blood test should be less than 5U/L, which means that it is back to normal. However, HCG does not return to the normal range immediately after the operation, it needs to decline gradually, usually returning to normal value in about 20 days after the abortion. One week after the operation, a blood test for HCG is needed. If the HCG drops compared with that before the abortion, it is considered normal, and monitoring can be continued until it returns to normal. Ultrasound is also needed one month after the operation to check the recovery of the uterus, if it has returned to normal, there is no problem.