Early pregnancy is an important period for the development of the embryo after its implantation. In the second trimester, the placenta has not yet formed, therefore, intercourse is not recommended in the early stages of pregnancy. After the embryo has completed the process of implantation, the fertilized egg gradually develops into functional organs and tissues. If you have intercourse during this period, the external force of intercourse may cause the embryo to become unstable, which may lead to miscarriage. In addition, intercourse increases the chances of vaginal inflammation. In early pregnancy, if vaginal inflammation is high, it can lead to miscarriage of the fetus under the influence of inflammation. If intercourse is inadvertent in the second trimester, there is no need to be overly concerned, as the above abnormalities are not certain to occur. The patient only needs to pay attention to the lower abdominal pain and observe the occurrence of vaginal bleeding. If there is no abdominal pain or vaginal bleeding, it can be observed temporarily without special treatment. If abdominal pain and vaginal bleeding occur, the patient is advised to consult a local hospital for gynecological ultrasound examination and, if necessary, hospitalization for fetal preservation. In conclusion, intercourse in the second trimester of pregnancy is a very dangerous act and will bring certain risks, so it is not recommended during early pregnancy.