Usually, postpartum uterine fluid will last until about 42 days after delivery. If there is a co-infection, the duration may be relatively longer. The process in which a little blood, meconium and endometrial necrotic tissue left in the uterine cavity after delivery are gradually absorbed or expelled through the vagina is known as malodex, which usually lasts about 4-6 weeks. If infection occurs during this period, inflammatory secretions may accumulate in the uterine cavity and cause fluid or pus accumulation in the uterine cavity. If the infection is not controlled in time, the retention time of fluid in the uterine cavity will be relatively longer. In addition, if there is still fluid in the uterine cavity after 42 days after delivery, you can go to the obstetrics and gynecology department of the hospital to clarify the cause of fluid accumulation and then take further treatment, and you need to pay attention to keep the vulva clean.