It is forbidden for women to have intercourse during their menstrual period. Because menstruation is a special period for women, the body’s immunity will decline during this period, the chance of infection will rise if you have intercourse, so having intercourse during this period will only have bad effects and no benefits. The main hazards are: a. The cervix is open during menstruation, which interferes with the process of menstruation during sexual intercourse, resulting in poor discharge of menstrual blood and abdominal pain. Second, male genitalia can bring bacteria into the infected endometrium, leading to pelvic inflammatory disease, causing pain to women. Third, it may cause infertility in women. IV. It may lead to endometriosis. V. For men, menstrual secretions may enter the urethra, thus causing urethritis.