The first 3 months of pregnancy should not have a conjugal life, in order to avoid adverse effects on the pregnant woman and the fetus. The first 3 months of pregnancy belongs to the early stage of pregnancy, the embryo has just begun to develop, and the connection with the uterine wall is not close enough, and the embryo is not yet stable in the uterine cavity. If sex occurs at this time may stimulate the uterus to contract, easy to cause abdominal pain, vaginal bleeding or miscarriage and so on. Moreover, early pregnancy sex such as poor hygiene habits, may allow pathogenic bacteria into the vagina to induce gynecological infections, once the pregnant woman suffers from gynecological inflammation is not good treatment, will lead to pregnant women discomfort or endanger the development of the fetus. Early pregnancy pregnant women will have different degrees of early pregnancy reaction, the body is easy to fatigue discomfort, sex may aggravate the fatigue discomfort. It is recommended to avoid sex in the first three months of pregnancy and the second three months of pregnancy, and have sex in the middle of pregnancy, pay attention to hygiene before and after sex, and avoid too frequent.