Low urea nitrogen and creatinine in pregnant women is often caused by pregnancy and not by disease, which means it is a normal physiological state. Low urea nitrogen and creatinine in pregnant women are mainly related to the following factors: 1. After pregnancy, women’s blood volume will increase significantly, and the amount of blood filtered through the glomerulus will increase, and the glomerular filtration rate will increase, which will increase the ability of the kidneys to detoxify the body, and therefore the urea nitrogen and creatinine will be low. 2. Pregnant women may eat less in the early stages of pregnancy, which can also lead to a low urea nitrogen and creatinine. The low urea nitrogen and creatinine will also result in the low urea nitrogen and creatinine. 3, because after the pregnant woman eats, part of the nutrition may be given to the fetus, so there will be a relative result of their own nutritional deficiencies.