If pelvic fluid develops during the rest period after induction of labor, no treatment is needed for the time being. Induced miscarriage is clinically known as late miscarriage. Late miscarriage is mostly called late because the embryo is relatively large. Because the pregnancy is often more than three months old, it takes a long time for the enlarged uterus to contract and return to its normal size after an induced abortion. During this period, there will be vaginal bleeding and malignant discharge, and as long as there is vaginal bleeding, it can flow backwards into the pelvic cavity with the contraction of the uterus and pelvic fluid will appear. Therefore, it is normal for pelvic fluid to appear in the puerperium after induction of labor and no treatment is needed. When the uterus has returned to its normal size and there is still pelvic fluid at the time of review, it is necessary to examine the cause and decide what kind of treatment should be done based on the examination.