The common causes of bruises on legs of pregnant women are as follows: 1, trauma: bruises on legs during pregnancy may be caused by trauma to the legs, causing rupture and bleeding of capillaries under the skin, resulting in bruises under the skin, which do not require special clinical treatment and usually disappear on their own in 1-2 weeks; 2, changes in hormone levels: pregnancy may cause a decrease in the number of platelets in the body, as well as a decrease in coagulation function, which may also lead to bleeding of capillaries and bruises on legs. 2, hormone level changes: pregnancy may cause the body’s platelet count and coagulation function to decrease, which will also lead to capillary blood seepage, and then lead to the phenomenon of bruising on the legs, usually after the birth of a child can return to normal. If a pregnant woman has unexplained bruises on her legs, it is recommended to go to the hospital for a routine blood test to observe whether there is a decrease in white blood cells, red blood cells, and especially platelets. In addition, a blood test for blood clotting is needed to see if the clotting mechanism is normal. If the tests are normal and there are no other abnormalities, it is recommended that pregnant women can take calcium tablets and multivitamin tablets by mouth, eat easily digestible food, eat more fresh vegetables and fruits, and avoid greasy, spicy and stimulating food.