The normal volume of the first menstrual period after delivery is between 20 and 60 ml, and rarely exceeds 100 ml, for both normal and caesarean women. If a woman has more than 100 ml of menstrual flow for the first time after delivery, it is often considered to be excessive, and it should be considered to be caused by poor uterine regeneration, resulting in an oversized uterus, or by poor contraction of the uterus, resulting in a significant increase in vaginal bleeding, so it is often necessary to go to the hospital for an ultrasound to see the size of the uterus and to rule out the presence of abnormal substances in the uterine cavity. It may also be due to the presence of fibroids or malformations in the uterus, which may affect the contraction of the uterus and cause excessive menstrual flow. Therefore, when excessive menstrual flow occurs, medication should be considered to stop the bleeding, usually by taking blood and caffeic acid tablets and, if necessary, estrogen, or scraping. Since the endometrium is usually thicker when menstruation resumes after childbirth, the menstrual volume at this time will be significantly higher than the usual menstrual volume.