Fetal arrest at 7 weeks of pregnancy may be due to chromosomal abnormalities of the embryo, uterine malformations of the pregnant woman, immune factors or infections, etc., which need to be analyzed specifically. 1. Embryonic chromosome abnormality: Embryonic chromosome abnormality is the most common reason for 7 weeks gestation arrest, embryonic chromosome abnormality will affect the genetic material of the embryo, affecting the growth and development of the embryo. 2. Abnormalities of the pregnant woman’s uterus: the pregnant woman’s uterus has abnormalities, which can’t provide a suitable place for the embryo, affecting the continued growth of the embryo. 3. Immune factors or infections: If there are immune abnormalities or intrauterine infections in the pregnant woman, so that the fetus can not adapt to the environment of the uterus, it can also make the embryo stop growing and developing. There are also other reasons why a 7-week abortion may not occur. A 7-week abortion needs to be treated in a timely manner, with the first step being to terminate the pregnancy and to identify the cause, so as to prevent the same situation from occurring in the next pregnancy. After the abortion, you need to take more rest and pay attention to hygiene to avoid infection.