What does it mean when your lips turn blue while pregnant?

Concerning: There are some normal pigment changes in the mucous membranes during pregnancy but serious medical conditions should be ruled out first. Low oxygen from lung disease such as asthma, pulmonary emboli, smoking and COPD should be excluded. Heart disease can causes this. Severe anemia is another possibility. Autoimmune disease such as lupus can also cause this. Some have blue lips when cold.