Yellow leukorrhea in pregnancy is usually caused by some gynecological diseases, such as vaginitis, pelvic inflammatory disease, cervicitis and so on. 1. Vaginitis: for example, fungal vaginitis or trichomonas vaginitis, which may be related to unclean sex, can lead to yellow leukorrhea, and accompanied by vaginal itching and leukorrhea and other symptoms. 2. Pelvic inflammatory disease: it may be related to unclean sex or poor hygiene, which may cause the leukorrhea to become yellow, and the amount of leukorrhea will increase, accompanied by symptoms such as abdominal pain. 3. Cervicitis: due to the presence of infection, can lead to yellowish leukorrhea, leukorrhea usually viscous liquid or purulent liquid, leukorrhea in the blood, there may also be irregular vaginal bleeding, pain during sexual intercourse and other symptoms. If you are pregnant and have yellowish leukorrhea, you may also have other abnormalities. It is recommended that you seek medical attention as soon as possible for checkups and treatments to avoid continued aggravation of the lesions, and to avoid premature rupture of membranes, miscarriages, and preterm deliveries due to infections and other undesirable outcomes of the pregnancy.