Clinical advice is that pregnant women should not have intercourse in the first trimester, and if they do, they should pay attention to hygiene and limit the number of times they have intercourse. In the first trimester of pregnancy, usually do not advocate pregnant women coitus. The reason is that the embryo is not yet stable in the first trimester, and coitus will stimulate uterine contractions, which will easily lead to miscarriage, and needs to be taken seriously. If there is a need, the first trimester should pay attention to personal hygiene, to prevent vaginitis, intrauterine infections and other conditions, in order to prevent the growth and development of the embryo. At the same time, the first trimester of pregnancy need to moderate the number of coitus, avoid frequent coitus, and coitus to avoid too large range of movement. After coitus, pay attention to observe whether you have abdominal pain, vaginal bleeding and other abnormalities, so that timely medical treatment measures. In addition to the first trimester, avoid intercourse in the last trimester to prevent premature labor. It is recommended to improve personal hygiene during pregnancy and to wear loose-fitting, cotton underwear as much as possible. It is also important to attend regular obstetric checkups during pregnancy to monitor the development of the fetus.