Intercourse is not recommended at 12 weeks of pregnancy. 12 weeks pregnant is the early stage of pregnancy, at this time you can not cohabit, cohabit will cause the possibility of preeclampsia. 12 weeks pregnant due to the placenta has not yet developed stable, the placenta and uterine wall connection is not close enough; and early pregnancy is a critical period of the formation of fetal body organs, at this time, coitus will affect the growth and development of the fetus will lead to preterm miscarriage. Therefore, it is not recommended to have intercourse in the 12th week of pregnancy. It is recommended to have intercourse in mid-pregnancy, that is, between 4-7 months of pregnancy can have intercourse, must pay attention to gentle movements. In addition, the frequency should not be too frequent. Before and after intercourse to wash the vulva, keep clean and hygienic. In addition, it is recommended that pregnant women in early pregnancy should keep their mood happy and learn to self-regulate. Diet should pay attention to balanced nutrition, prohibit smoking and alcohol; moderate exercise, not strenuous exercise; regular maternity checkups, testing blood sugar, blood pressure, thyroid function and so on.