The increase of yellow discharge from the vagina in pregnancy is mainly due to the hormonal secretion of the body in the early stage of pregnancy, the gestational sac is still unstable, and the secretion of the endometrium, cervix, and vagina will be increased, so there will be yellow discharge. In addition, pathological factors can also lead to yellow discharge in pregnancy, such as bacterial vaginitis, trichomoniasis, mycosis vaginalis, cervicitis, or hormone level metabolic disorders, endocrine disorders and other reasons. Routine secretion and auxiliary examinations such as gynecological ultrasound are needed to know whether there is a substantial pathogenic bacterial infection. If the increase in discharge is caused by vaginitis, it can also be treated with medication during pregnancy, but you need to choose the medication under the guidance of the doctor and avoid blindly and indiscriminately using antibiotics, otherwise it may affect the fetus.