How many months pregnant can you not sleep together

In early pregnancy, especially in the first trimester of pregnancy and three months after pregnancy can not be the same room, because sexual life can cause threatened abortion, premature delivery, premature rupture of membranes, placental abruption and other manifestations. If pregnant women in general good condition, in pregnancy 4 to 6 months, if there is no abdominal pain, vaginal bleeding cervical canal shortening, placenta low state can be appropriate in the same room, but the same room needs to use condoms, because the prostaglandin in semen will induce uterine contractions caused by abortion.