Generally, it refers to the uterus not contracting or poor contraction after delivery or abortion, and the causes of this symptom mainly include: poor uterine contraction after full-term delivery is generally caused by the body of the mother is too tired in the process of delivery; or caused by excessive mental tension and stress during delivery; some mothers use painkillers and sedatives during delivery, which also affect the function of uterine contraction after delivery. Some women use analgesics or sedatives during delivery, which will also affect the contraction function of the uterus after delivery and cause poor uterine contraction; after delivery or abortion, there are placenta, fetal membranes and other tissues left in the uterine cavity, and if there are a lot of residues, it will lead to poor uterine contraction; after delivery or abortion, if you lie in bed for a long time, you will not be able to move around, and a lot of clots of blood will be left in the uterus, which will affect the normal contraction function of the uterus, and will lead to poor or no uterine contraction.