Pseudomenorrhea is the transmission of estrogen from the mother to the fetus at the end of pregnancy, and this endocrine hormone has the effect of stimulating the proliferation and congestion of the mucous membranes of the female infant’s reproductive tract. After birth, as the source of estrogen from the mother is interrupted, the concentration of estrogen in the baby girl’s body drops sharply, to a very low level after 3-5 days, and the supporting effect of estrogen on the proliferation and congestion of the reproductive mucosa is interrupted. As a result, the endometrium, which had been proliferating and engorged with blood, is shed, causing the baby girl to discharge a small amount of blood and some bloody discharge from the vagina, which is similar to menstruation. It usually occurs 3-7 days after the birth of the baby and lasts for about 1 week. Since the bleeding is very small, this phenomenon can be allowed to develop naturally and does not need to be treated by a doctor. For the small amount of blood and discharge coming out of the vagina, it can be accompanied or not accompanied by urine and gently wiped away with sterile gauze, but not with local dressing, which can cause infection.