If a pregnant woman does not have a pre-eclampsia or other uncomfortable conditions, intercourse is appropriate between the 12th and 28th weeks of pregnancy, i.e., mid-pregnancy. The entire pregnancy is divided into 3 stages: early pregnancy, middle pregnancy and late pregnancy. Early pregnancy refers to the period before the 12th week of pregnancy, which is an important period for the formation of the fetus and is prone to miscarriage, so for the safety of the fetus, intercourse is not recommended. The middle pregnancy refers to the period between 13 and 27 weeks, during which the fetus is already formed and not too big, the pregnant woman’s stomach is not too big, so it is easy to move around and the uterus is not very sensitive, so it is not easy to cause contractions, so it is relatively safe to have intercourse. The late pregnancy period refers to after 28 weeks of pregnancy, the belly gradually grows, less convenient to move, and the uterus is more sensitive, stimulation will easily cause contractions, so coitus is not recommended. Intercourse should also pay attention to the frequency, degree and hygiene, and avoid strongly stimulating the nipples or cervix of pregnant women. It is also recommended to use condoms to avoid irregular contractions caused by prostaglandins in the semen, and to prevent the spread of sexually transmitted diseases. At the same time, pregnant women should clean the vulva area well to avoid vaginal and urinary tract infections. During or after sex, attention should be paid to the condition of the mother and the fetus, and any discomfort or abnormality needs to be seen promptly. Sexual intercourse is not recommended in early and late pregnancy to avoid causing preterm abortion or redness, premature rupture of fetal membranes, intrauterine fetal infection and other hazards.