Short communication: imaging pulmonary embolism in pregnancy: what is the most appropriate imaging protocol?

Pulmonary embolism is the leading cause of death in pregnancy. Despite the difficulties in clinical diagnosis and the concerns regarding radiation of the fetus, the British Thoracic Society guidelines for imaging pulmonary embolism do not specifically address the issue of imaging for pulmonary embolism in this group. This communication discusses the difficulties of diagnosis and imaging pulmonary embolism in pregnancy and proposes a suitable imaging protocol. Clinical exclusion of patients from further imaging is recommended if the patient has a low pre-test probability of pulmonary embolism and a normal d-dimer. It is advised that all remaining patients undergo bilateral leg Doppler assessment. If this test is positive, the patient should be treated for pulmonary embolism; if negative, all patients should be referred for CT pulmonary angiography. Ideally, informed consent should be obtained prior to CT scanning. All neonates exposed to iodinated contrast in utero should have their thyroid function tested in the first week of life due to the theoretical risk of contrast induced hypothyroidism.