Carrying out coitus in the second trimester of pregnancy may cause the adverse consequences of fetal arrest, because in the second trimester of pregnancy, the embryo itself is unstable in its development, and the hormone level is also unstable, so it is not possible to carry out sexual intercourse during this period. Engaging in sexual intercourse is not good for your health, it will cause edema of the mucous membranes of the vaginal tissues and the contraction of the uterus, which may cause the fetus to stop developing, and may even lead to consequences such as miscarriage. If there is obvious vaginal bleeding, abdominal pain, you need to go to the hospital in time to check the ultrasound, serum Hcg and progesterone values, if there is a decline in hormone levels, it is suggestive of signs of miscarriage, you need to take bed rest, timely selection of medication to preserve the fetus treatment for a week after the review. If it has been determined that the fetus has stopped, you need to take appropriate abortion measures to prevent the occurrence of infections and other complications, 10 days after the abortion or after the next menstrual period should also be ultrasound recheck, six months before the preparation for pregnancy.