The time of menstruation after cesarean section is very much related to the duration of breastfeeding, maternal age factor and physical condition, most of the mothers with cesarean section will return to normal menstruation in 8-24 weeks after delivery in the following cases: 1. Breastfed mothers will have menstruation in about 3 months after delivery, and non-breastfeeding mothers will return to normal ovulation in about 6 weeks after delivery. 2. Mothers aged between 25-30 years old, with better physical condition and faster recovery of ovarian function, may have menstruation in about 2 months after delivery. 3. Mothers between the ages of 25 and 30, who are in good health and have faster recovery of ovarian function, may start menstruation about 2 months after delivery.3 Mothers between the ages of 30 and 35 years old will take longer to resume menstruation. If menstruation has not resumed more than 6 months after delivery, the thickness of the uterine lining can be monitored and the time for resumption of menstruation can be budgeted according to the thickness of the uterine lining.