While coughing up blood while pregnant can be a common side effect of bronchitis, it can also signify more serious illnesses, such as lung cancer, pneumonia, pulmonary embolism, congestive heart failure, tuberculosis or an auto-immune disorder, according to WebMD. WebMD advises that coughing up blood at any point during a pregnancy is an extremely serious situation and requires an urgent call to a doctor.
Hemoptysis, or the coughing up of blood, can be caused due to infection, cancer and problems in the lungs or blood vessels, according to WebMD. Any sort of difficulty breathing, chest pain or coughed up blood should never be ignored during pregnancy, as these problems can put both the mother and unborn child at serious risk, according to BabyCenter. Medical professionals utilize a series of different tests to determine the exact cause of the bleeding, including: a chest X-ray, CT scan, bronchoscopy, complete blood count, urinalysis and coagulation tests, according to WebMD. In some cases, the cause of the bleeding may never be identified and in other cases the bleeding can be traced to sources outside of the lungs, such as a nosebleed or vomiting up blood that has drained into the windpipe, according to WebMD.