Not usually. Enjoying sex while you’re pregnant is a safe and healthy thing to do
The only exceptions are if you’ve had a threat of miscarriage, a prior preterm birth, if your cervix is incompetent or dilated, or if you’re experiencing unexplained vaginal bleeding or discharge. In those situations, certainly discuss your concerns with your doctor.
All women experience uterine contractions during orgasm. They’re caused by prostaglandins, substances found in semen and some bodily tissues, explains Dr. Stewart. You just feel these contractions more intensely now because your uterus is swollen and your blood flow is increased. But in a normal pregnancy these contractions won’t cause you to lose the baby. Your unborn child is well padded against any sexual acrobatics by the fluid-filled amniotic sac and strong uterine muscles, and he’s guarded from infection by a thick mucus plug that seals the cervix.