Running watery discharge at seventeen weeks of pregnancy may be premature rupture of fetal membranes, or it may be caused by vaginitis and other diseases. 1. Premature rupture of membranes: If a pregnant woman is malnourished and lacks vitamins and trace elements such as copper and zinc, it is easy to cause the membranes to become brittle and induce premature rupture of membranes. If the pregnant woman herself has cervical insufficiency, or the position of the fetus is abnormal, the pressure in the uterine cavity increases, which will stimulate the fetal membranes, leading to premature rupture of the membranes and the appearance of watery discharge. 2. Vaginitis: After pregnancy, a woman’s body immunity will decline, and the vulva and vagina will be easily attacked by bacteria, leading to the emergence of vaginitis or aggravation of the symptoms of vaginitis, which will be manifested in abnormal vaginal discharge, and watery discharge may appear. Seventeen weeks of pregnancy watery discharge may be abnormal, and you need to go to the hospital for relevant examinations to clarify the cause and treatment.