Pulmonary embolism during pregnancy: a 17-year single-center retrospective MDCT pulmonary angiography study

Vesna Ilic,Sabine Schmidt,Vincent Dunet,David C Rotzinger,Reto A Meuli,Olivier W Hugli

doi:10.1007/s00330-019-06501-4

Abstract

ObjectivesTo determine the prevalence of pulmonary embolism (PE) and alternative diagnoses detected by computed tomography pulmonary angiography (CTPA) in pregnant women; and to assess changes over time regarding radiation dose, technical quality, and examination frequency.Materials and methodsThis retrospective study included all pregnant women referred for CTPA due to clinically suspected PE over 17 years. Two blinded radiologists reviewed the CTPAs in consensus with regard to PE, alternative diagnoses, and technical quality. We retrieved patient data regarding radiation dose metrics and associated clinical and laboratory parameters. Subgroup comparisons were performed (Wilcoxon and Kruskal-Wallis tests).ResultsOf the 237 identified patients, 8 (3.3%) were excluded due to inadequate technical CTPA quality, and 229 patients were analyzed (mean age, 31.7 years; mean gestational age, 28 ± 7 weeks). The four different CT systems used over the study period had similar technical quality (p = 0.28). Of 229 patients 16 (7%) patients had PE, 144 (62.9%) had no abnormal findings, and 69 (30.1%) had an alternative diagnosis (consolidation, other pulmonary opacities, pleural effusion, and basal atelectasis). Gestational age, symptoms, and D-dimer levels were not significantly different between patients with or without PE (p > 0.05). Over time, radiation dose exposure decreased by 30% (p < 0.001), while the number of annual examinations increased by > 4-folds.ConclusionsIn pregnant women, CTPA rarely indicates PE and more often shows alternative diagnoses. Over 17 years, the use of CTPA in pregnancy has notably increased, while the radiation dose exposure has decreased by one third.Key Points• The use of CTPA in pregnancy has steadily risen over the last 17 years• In pregnant women, CTPA rarely reveals PE and more often shows alternative diagnoses• Recent technical improvements have substantially decreased the radiation dose exposure inherent in CTPA without reducing diagnostic image quality

Highlights

Study design and patientsPregnancy induces a prothrombotic state, with increased coagulation factors, decreased natural anticoagulants, and impairment of fibrinolysis
Our current results including 229 pregnant women indicate that 7% had acute pulmonary embolism (PE), 30% had alternative diagnoses, and 63% had a normal computed tomography pulmonary angiography (CTPA)
This low prevalence of PE indicates that CTPA was mainly useful for excluding PE in this population

Summary

Introduction

Pregnancy induces a prothrombotic state, with increased coagulation factors, decreased natural anticoagulants, and impairment of fibrinolysis. This hypercoagulable state most likely evolved during pregnancy to protect women from the risk of bleeding during miscarriage and childbirth. Several factors can increase the risk for venous thromboembolism (VTE) during pregnancy, including inherited thrombophilia, antiphospholipid syndrome, or previous history of thrombosis [1,2,3]. Compared to the non-pregnant population, pregnancy increases the risk of deep vein thrombosis (DVP) and pulmonary embolism (PE) by at least four times. PE is the leading non-obstetric cause of maternal death, with death occurring in 1 of 100 pregnant women diagnosed with PE [4]

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