Hello dear, First of all congratulations for your pregnancy and welcome to Healthcare Magic. I read your query and I understand your concern. Compared with most other live vaccines, which are contraindicated in pregnancy, Yellow Fever vaccine administration is considered a precaution. Since you didn t know about your pregnancy before you traveled to an endemic area, the risk from the disease and the theoretical risk from the vaccine has to be assessed on an individual basis. Yellow fever vaccine has been assigned to pregnancy category C by the FDA, which means that animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Hope I helped with my answer. For further concerns feel free to ask again. Wishing you god health, Dr. Ina