Cesarean scar diverticulum is a defect in the continuity of the myometrium that occurs after cesarean section due to poor healing of the scar. The causes of cesarean diverticula may be related to the location of the cesarean incision, the healing of the cesarean incision, and the suturing technique used to close the incision during the cesarean delivery. Women with cesarean scar diverticula may present with irregular vaginal bleeding. Possible causes include weak muscular layer of the cesarean scar and weak contraction, resulting in retention of menstrual blood within the diverticulum and irregular postmenstrual vaginal bleeding. If the residual thickness of the myometrial layer in the anterior wall of the uterine scar is less than 2.2 mm, it is defined as a large diverticulum. The treatment of diverticula varies with the individual, the diverticulum and the severity of clinical symptoms. Once the diagnosis is confirmed, surgery can be considered as the first choice. However, the size of the diverticulum should not be the only indication for surgery. With the liberalization of the two-child policy, women who get pregnant again after cesarean section will face the risk of keloid pregnancy (the gestational sac resting on the scar), so it is recommended that women after cesarean section should have an ultrasound review as soon as possible after the early pregnancy to clarify the location of the gestational sac and to avoid the emergence of untreatable keloid pregnancy. It is also recommended that moms and dads who are ready to conceive a baby have a vaginal delivery as their first choice.