In the fourth month of pregnancy, you can have intercourse appropriately. This is a relatively safe period because the fetus is already mature and in the middle of the pregnancy; the abdomen is not particularly bulging at this time, so the impact on the fetus will not be great; the cervical canal is also longer at this time, so it will not stimulate the gestational sac and will not stimulate the amniotic sac and cause the water to break. When having intercourse during this period, you should also try to be careful not to move too roughly to avoid pressing on the abdominal cavity and affecting the fetus. In the first three months of pregnancy and the second three months of pregnancy generally try not to have intercourse, because then it is easy to affect the fetus, which may cause a miscarriage or premature birth. In the second trimester, if the intercourse is too violent, it can easily cause the water to break, resulting in infection of the uterine cavity or the possibility of premature rupture of the fetal membranes.