It is very unlikely that the embryo will stop during intercourse in the second trimester. The embryo is unstable during this period and intercourse causes uterine contractions, which can easily lead to preterm abortion. The main reason for embryonic abortion in early pregnancy is caused by poor embryonic development. 1, chromosomal abnormalities: whether sperm or egg, as long as the chromosomes carrying genetic material are abnormal, even if a fertilized egg is formed, the embryo will not develop normally. Therefore, if there is a history of genetic disease in the family, medical diagnosis and pre-conception physical examination should be carried out before pregnancy. 2. Uterus abnormalities: the overall environment in the uterus is not good, inflammation, thin endometrium can have an impact on the development of the embryo. Some data indicate that miscarriage due to uterine defects clinically accounts for about 10%-15%, resulting in fetal arrest also accounts for about 10%. 3, pregnant women have their own chronic diseases: pregnant women have serious chronic diseases, such as diabetes, hypertension, heart disease, viral hepatitis, malnutrition, endocrine disorders, etc., due to long-term drug treatment, which has an impact on the life and health of the fetus. 4. Exposure to harmful substances, cold and illness during pregnancy may cause embryonic abortion. You can’t have intercourse at the beginning of pregnancy, not because it causes embryonic abortion, so don’t get too hung up on it.