Causes of black stools during pregnancy: First, caused by drugs, during pregnancy, if pregnant women take oral iron supplements for blood, herbs for stomach problems, may cause the stool to become black. Second, systemic infectious diseases caused by pregnant women suffering from sepsis, typhoid, etc., may cause black stool. Third, caused by blood diseases, black stool during pregnancy may be caused by hemophilia, leukemia, thrombocytopenia and allergic purpura. Fourth, food caused by certain foods may cause changes in the color of the stool, sometimes easily confused with blood in the stool, such as after eating animal blood or large amounts of beef, pig liver, the iron in which can be formed in the human intestine black iron sulfide, so that the color of the stool becomes black. If a large number of eating prune jam, mulberry jam are likely to cause the color of the stool to become black. Fifth, the digestive tract diseases caused by, including cirrhosis combined with esophageal and gastric fundic varices rupture, acute gastritis, ulcers can cause stool color change.