The common causes of excessive vaginal discharge during pregnancy include: 1. In early pregnancy, if there is an increase in vaginal discharge but no obvious itching and odor symptoms, it is mostly considered a normal physiological phenomenon caused by the increase in cervical secretion and vaginal wall exudate due to the change in hormone level in the body after pregnancy. 2. If the symptoms are accompanied by itching and odor, it is considered to be caused by gynecological inflammatory diseases such as cervicitis and vaginitis during pregnancy. 3. If the symptoms occur in the middle and late stages of pregnancy, you should also be highly alert to the possibility of premature rupture of the fetal membranes and amniotic fluid outflow, which generally manifests as continuous watery discharge and increases in the amount of outflow during activity.