26 weeks pregnant can not breathe, may be too large uterine compression, pregnancy and respiratory diseases, pregnancy and heart disease and so on caused by the manifestation. 1. Overlarge uterus compression: at 26 weeks of pregnancy, the fetus grows more obviously in the uterine cavity, and there is amniotic fluid in the uterine cavity as well as the placenta and other appendages, which may cause the uterus to increase significantly, which may compress the heart and cause the pregnant woman to be unable to catch her breath. 2. Combined respiratory diseases of pregnancy: at 26 weeks of pregnancy, if the pregnant woman has combined acute and chronic bronchitis, pneumonia, chronic obstructive pulmonary disease and other respiratory diseases, respiratory dysfunction, there may be breathlessness. 3. Combined pregnancy heart disease: If the pregnant woman in the 26th week of pregnancy, there are combined pregnancy congenital heart disease, wind heart disease, cardiac insufficiency and other heart diseases, which may lead to abnormal blood supply function of the heart, it may cause breathlessness. If a pregnant woman is out of breath at 26 weeks of pregnancy, she needs to go to the hospital in time for diagnosis and treatment of her condition to avoid serious consequences.