The causes of flatulence during pregnancy, there are the following: 1, due to the growth and secretion of hormone levels during pregnancy, will slow down the smooth muscle peristalsis of the gastrointestinal tract, flatulence, belching and other symptoms, the digestive system is affected, causing the most powerful flatulence, after which it will slowly improve, which is also a normal phenomenon, do not worry excessively. 2, the uterus becomes larger, with the increasing size of the uterus during pregnancy will press the intestines, affecting intestinal peristalsis. If the pregnant woman has constipation and gastrointestinal peristalsis before, it will also appear during pregnancy. 3, improper diet, not to develop good eating habits, overeating, eating raw, cold, unclean, greasy, spicy, stimulating food. 4, affected by the environment, weather, temperature, etc., not pay attention to keep warm. 5, do not exclude other digestive system diseases caused by, can further do medical detailed examination to clarify the cause and treatment direction.