If the pregnant woman does not have pre-miscarriage, and other uncomfortable conditions, it is possible to have intercourse appropriately between the 12th week of pregnancy and the 28th week of pregnancy, i.e., the mid-pregnancy. The entire pregnancy is divided into 3 stages: early, mid and late pregnancy. Early pregnancy refers to the period before the 12th week of pregnancy, which is an important time for the fetus to take shape and is prone to miscarriage, so for the safety of the fetus, coitus is not recommended. Middle pregnancy refers to the period between 13-27 weeks, during this time the fetus has been molded, and not too big, the pregnant woman’s belly is not big, easy to move, the uterus is not very sensitive, not easy to cause contractions, so coitus is relatively safe. Late pregnancy refers to 28 weeks after pregnancy, the stomach gradually grows, activities are not very convenient, and the uterus is more sensitive, stimulation is easy to cause contractions, so coitus is not recommended. The frequency, degree and hygiene of coitus should also be paid attention to, avoiding strong stimulation of pregnant women’s nipples or cervix. The use of condoms is also recommended to avoid irregular contractions caused by prostaglandins in semen and to prevent the spread of sexually transmitted diseases. At the same time, pregnant women should keep their vulvar area clean to avoid vaginal and urethral infections. During or after sex, attention should be paid to the condition of the mother and fetus, and any discomfort or abnormality requires prompt medical attention. It is not recommended to have sex in early and late pregnancy to avoid causing pre-eclampsia or redness, premature rupture of membranes, intrauterine infection and other hazards.