Pregnant women should not have sex during the first and second trimesters of pregnancy. In the middle of pregnancy, which is relatively stable, coitus can be appropriate, but care should be taken to ensure hygiene and gentle movements. When pregnant women are in the first 3 months of pregnancy, the implantation of the pregnant egg is unstable, and during coitus, sexual excitement may stimulate the uterus or exert undue pressure on the abdomen, inducing contractions and bleeding, which may lead to preterm miscarriage, abortion and other conditions. At the same time, coitus will interfere with the vaginal flora and may induce vaginitis. Therefore, coitus is not recommended in the first 3 months of pregnancy. While the fetus is larger in the second 3 months of pregnancy, pressure on the abdomen during coitus can compress the fetus. At the same time, coitus will stimulate the uterus to cause contractions, which may cause premature rupture of membranes and lead to preterm labor. Therefore, coitus should be strictly prohibited in the first and second trimesters of pregnancy. In addition, pregnant women should pay attention to avoid strenuous activities during pregnancy, reduce abdominal impact, avoid exposure to toxic and harmful substances. At the same time, they should pay attention to rest, eat a balanced diet and take regular pregnancy tests.