As we know, the normal uterus is a cavernous organ covered with mucous membrane (i.e. endometrium), which has important functions. From puberty to menopause, the endometrium is influenced by ovarian hormones and grows and sheds periodically (menstruation); during sexual intercourse, the uterine cavity is the necessary passage for sperm to reach the fallopian tubes; during pregnancy, the endometrium is the place where the embryo is laid and develops; during childbirth, the fetus and its appendages are expelled from the uterine cavity by uterine contractions. The primordial uterus, also known as the trace uterus, is a manifestation of the undeveloped uterus. During fetal life, the female genitalia are formed by the rendezvous of the two paramedian tubes, and the primordial uterus is the result of the cessation of development soon after the rendezvous of the two paramedian tubes. This type of uterus is extremely small (only 1-3 cm long), with no uterine cavity, no endometrium, no menstruation, and no vagina. On ultrasound, it can be seen that the uterus looks like a cord and has no cavity wave. Because of the absence of a cavity and endometrium, the primordial uterus is not fertile and has no therapeutic value. Uterine dysplasia, also known as infantile uterus, is caused by the cessation of the development of the two paramedian tubes for a short period of time after their reunion. The uterus is smaller than normal, often extremely anteflexed or retroflexed, but has a cavity (cavity covered with endometrium); the cervix is conical, relatively long, and has a ratio of 1:1 or 2:3 (normal is 2:1) to the body of the uterus; the patient has very few menstrual periods and does not have children after marriage; however, the infantile uterus can increase in size after regular treatment, and some people can even get pregnant. What we need to tell you is that the general public is not sure what is going on with infantile uterus and primordial uterus because they do not have gynecological knowledge. If a girl does not menstruate or has abnormal menstruation when she reaches puberty, she should go to a regular hospital for examination as soon as possible, so that some girls with infantile uterus can get timely treatment and thus have the possibility to make them fertile.