There is no effect of internal ejaculation in mid-pregnancy coitus. In the middle of pregnancy, the embryo development is relatively large, the placenta development is also relatively good, so the whole embryo is relatively stable. Therefore, coitus at this time generally will not cause uterine contractions or cause miscarriage. In addition, during pregnancy, the patient’s estrogen and progesterone levels are very high, and the cervical mucus is thicker and more abundant, so even if there is ejaculation in the coitus, the sperm will not penetrate the patient’s cervical mucus and enter the patient’s uterine cavity. And at this time the patient will not occur ovulation, so in this case the patient will not appear again the situation of unwanted pregnancy. But in the mid-pregnancy coital ejaculation, must pay attention to the coital strength, not too big, and must pay attention to hygiene, to avoid the occurrence of infection.