In principle, sexual intercourse during pregnancy is not necessary, but if the sexual partner is in the state of UTI or virus carrier, it is recommended to have protected intercourse, that is, condom intercourse. If a man has a urinary tract disease, local inflammation is evident, and bacteria multiply, unprotected intercourse can be transmitted to the pregnant woman. The resistance during pregnancy itself is weak, and infected bacteria are more likely to lead to vaginitis, cervicitis and other diseases in pregnant women, or even retrograde infection, leading to intrauterine infection, causing miscarriage, premature birth and other situations. If a man is carrying the papilloma virus, it can cause the virus to infect the pregnant woman and cause cervical lesions during pregnancy.