1. Malnutrition and diseases: In addition to congenital uterine dysplasia, adolescent malnutrition or chronic diseases can also cause reproductive organ dysplasia and insufficient ovarian hormone secretion.

2. Abnormal uterine position: The normal uterine position leans forward, the uterine body is slightly forward, and the cervix is downward and backward. After sexual intercourse, due to the accumulation of semen in the posterior fornix of vagina, the downward cervix is easy to soak in semen, which is conducive to sperm swimming upward.

3. Endocrine factors: Many women with uterine dysplasia are related to endocrine factors, which are caused by endocrine disorders, especially the lack of estrogen and progesterone secretion caused by ovarian dysfunction.

4. Pituitary-hypothalamus-ovary abnormality: Under normal circumstances, after a woman matures, if there is a "fault" in the pituitary, hypothalamus, ovary and other organs, the development of the uterus will be slow.