The third trimester fetal arrest may be caused by chromosomal abnormalities, endocrine disorders, uterine environment abnormalities and other reasons. 1. Chromosomal abnormality: it is a common factor that leads to the occurrence of fetal arrest in the early stages of pregnancy. Whether it is a woman’s egg or a man’s sperm, as long as it carries genetic inheritance and chromosomal abnormality, even if the sperm and egg combine and develop into a fertilized egg, the embryo will not be able to develop normally, thus resulting in the occurrence of third trimester fetal arrest. 2. Endocrine disorders: If the hormones in the mother’s body are insufficient to meet the needs of embryonic development, it may cause embryonic arrest. 3. Abnormal uterine environment: If a woman’s intrauterine environment is not good, such as the presence of congenital uterine abnormalities, cervical dysplasia, the occurrence of uterine adenomyosis, uterine fibroids and so on, it will affect the growth and development of the embryo. If a pregnant woman has a situation where the embryo stops developing in the third trimester, it is recommended that she consult a doctor in time, and under the guidance of the doctor, improve the relevant examinations to clarify the cause of the disease and treat the symptoms.