(644) Diagnostic rate of Pulmonary Embolism during pregnancy: An update on VQ vs CT

Thursday, January 30, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Suzanne O'Nan, MD (she/her/hers)

Maternal Fetal Medicine Fellow
University of Minnesota
Minneapolis, Minnesota, United States

Coauthor(s)

Julia Burd, MD

Fellow
Washington University in St. Louis
St. Louis, Missouri, United States
NR

Nandini Raghuraman, MD, MSCI

Assistant Professor of Ob&Gyn
Washington University School of Medicine in St. Louis
St. Louis, Missouri, United States
Antonina I. Frolova, MD, PhD (she/her/hers)

Assistant Professor of Ob&Gyn
Washington University School of Medicine
St. Louis, Missouri, United States
MD

Michael Dombrowski, MD

Assistant Professor
Washington University in Saint Louis
St. Louis, Missouri, United States
RR

Roxane Rampersad, MD

Washington University in St. Louis
St. Louis, Missouri, United States
Jeannie C. Kelly, MD, MS (she/her/hers)

Associate Professor
Washington University School of Medicine in St. Louis
St. Louis, Missouri, United States

Objective: Diagnosing pulmonary embolism (PE) during pregnancy can be challenging. We sought to compare PE diagnosis rates during pregnancy based on the original imaging modality of ventilation-perfusion (VQ) scan versus CT angiography (CTA).

Study Design: We performed a retrospective chart review of pregnant participants who underwent either VQ scan or CTA due to clinical suspicion of PE from January 2018- April 2024 at a single academic institution. Patients who underwent imaging for other clinical reasons, postpartum patients, and deliveries at an outside hospital were excluded. Our primary outcome was a scan considered diagnostic by the radiology read. Secondary outcomes included if a second imaging modality was pursued for diagnosis and reasons why initial imaging was non-diagnostic. Chi-squared, Fisher’s exact, Student’s t and Wilcoxon Rank sum tests were used as appropriate.

Results:

113 patients were included; 80 (71%) were imaged by VQ scan, and 33 (29%) were imaged by CTA. Baseline demographics and major VTE risk factors were similar between groups, including BMI and trimester of pregnancy; most patients were in the third trimester (Table 1). Diagnostic rates were similar between VQ and CTA groups (62.5% v 72.7%, P=0.29), and 33.3% of patients in each group with non-diagnostic findings underwent further testing to evaluate for PE (Table 2). PE was present in a minority of patients in both cohorts, and most non-diagnostic scans were due to poor timing of dye/opacification of vessels (Table 2).

Conclusion: Despite improvements in technological imaging studies, many studies of both VQ and CTA are non-diagnostic to exclude PE in pregnancy. Causes for non-diagnostic imaging studies should be investigated in the future.