Dark yellow discharge in the morning in the third trimester of pregnancy is considered to be a normal phenomenon, vaginitis, cervicitis and so on. 1. Normal phenomenon: after pregnancy, women have higher levels of estrogen and progesterone, which will cause an increase in vaginal secretions, and if the secretions are not washed away in time, the secretions will also be yellow. This situation is normal, usually there is no vulvar itching, discharge odor discomfort symptoms. 2. Vaginitis: After pregnancy, the immunity of women’s body will be reduced, if you do not pay attention to personal hygiene, it is more likely to cause inflammation of the vaginal area of the infection, there will be an increase in the number of vaginal secretions, the color is abnormal, as well as odor and other symptoms, usually accompanied by symptoms of itching. 3. Cervicitis: Cervicitis is mainly caused by pathogens infecting the cervix, which may be sexually transmitted pathogens or endogenous pathogens. Inflammatory stimuli will lead to an increase in leucorrhoea, which is usually grey or yellowish, purulent and accompanied by a peculiar odor. The dark yellow discharge in the morning of the third trimester of pregnancy may also have other causes, it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.