1. Causes of dyspnea in pregnant women 1.1 Dyspnea caused by physiological changes during pregnancy During pregnancy, due to the increase in size, the diaphragm and lungs are compressed, causing difficulty in breathing. In addition, changes in hormone levels in pregnant women can also affect breathing, making breathing difficulties more obvious. 1.2 Dyspnea caused by pregnancy complications. Some common complications during pregnancy, such as pregnancy-induced hypertension, anemia, heart disease, etc., may cause