There are two possibilities for slight yellowing of the color of the leukorrhea in the third trimester of pregnancy, one is a physiological change and the other is caused by vaginal inflammation. With the changing hormone levels in the body, women who are pregnant will experience a certain degree of increase in vaginal secretions and may experience changes in the status of the leucorrhea. As long as there is no obvious vaginal itching or serious odor, it is normal. You should pay attention to personal hygiene in general, such as bathing and changing underwear regularly, to effectively improve this symptom. However, after pregnancy, vaginal discharge will increase significantly and the chance of inflammation will also increase significantly. If there is odor or itching at the same time, it is necessary to determine whether there is inflammatory infection by routine examination of the white belt. If there is inflammatory infection, such as bacterial vaginitis, mycotic vaginitis or trichomoniasis, it can be treated by using the corresponding topical medication, which will not affect the fetal development.