A large stomach after childbirth is usually caused by accumulation of abdominal fat, water and sodium retention in the body, and incomplete recovery of the uterus. 1. Accumulation of abdominal fat: During pregnancy, pregnant women eat a lot of highly nutritious food, resulting in thickening of abdominal fat. 2. Water and sodium retention in the body: During pregnancy, the retention of water and sodium in the body due to hormones will lead to abdominal edema. After delivery, with the gradual decline in hormone levels, stomach edema will slowly recover, and will not return to normal at once. 3. The uterus is not fully recovered: due to the gradual shrinkage of the uterine body after delivery of the placenta, the uterus shrinks to about 12 weeks of gestation in the first week after delivery, and returns to its pre-pregnancy size in the sixth week after delivery. Large postpartum stomach may also be caused by poor uterine contraction, if there is no recovery for a long time, you need to consult a doctor for examination.