Diagnosing Pulmonary Embolism During Pregnancy

Abstract

Topic importance: Pulmonary embolism (PE) is one of the leading causes of pregnancy-related deaths in high-income countries. Maternal mortality from PE has been attributed to delayed recognition and investigation. The diagnosis of PE may be challenging, as its early signs and symptoms may overlap with physiological changes of pregnancy. As such, promptly ruling out suspected PE using diagnostic testing is of paramount importance. This narrative review provides a contemporary overview of risk assessment tools, diagnostic modalities, counseling needs, and existing best practice guidance for the diagnosis of PE in pregnancy.

Review findings: The revised Geneva score and the pregnancy-adapted YEARS algorithm are promising risk stratification methods that have been found to be safe and effective to support the diagnosis of PE in pregnancy. CT pulmonary angiography and ventilation perfusion scans have comparable safety and effectiveness profiles. Iodinated contrast agents administered for CT pulmonary angiography in pregnant patients with suspected PE are not associated with risks of neonatal adverse events. Pregnant patients may experience distress about fetal health during diagnostic testing, underscoring the importance of counseling to help in decision-making and improve the quality of care. Recent guidelines have supported the use of clinical prediction rules. Both imaging modalities are considered safe in pregnancy, with some guidance advising to choose between the 2 tests based on chest radiography results.

Summary: The choice of diagnostic testing should be based on equipment availability, the ability to perform testing in a timely manner, clinical urgency, chest radiography results, and suspicion of alternative diagnoses.

Keywords: CT pulmonary angiography; imaging; pregnancy; pulmonary embolism; severe maternal morbidity; venous thromboembolism; ventilation-perfusion scintigraphy.