Introduction
Pulmonary embolism (PE) is uncommon in pregnancy, however remains a major cause of maternal mortality in Australia. Assessment in pregnancy remains clinically challenging.
Objectives:
Retrospective observational series of pregnant women undergoing diagnostic imaging for suspected PE to assess incidence and clinical factors associated with a positive diagnosis and use of ancillary tests.
Methods:
Ventilation/perfusion (VQ) scans and computer tomography-pulmonary angiography (CT-PA) performed at a single centre from 2014-2016 on pregnant and post-partum women under the age of 45years were reviewed. Clinical information was obtained from patient records.
Results
141 scans (15 CT-PA, 126 VQ) were performed on 136 women. Average age 31years (±5), average BMI 27.7kg/m2 (±7.1). Ten were diagnosed with PE (incidence 7%). All CT-PA were non-diagnostic or negative.
Although 55% of women presenting were in the third trimester, post-partum was highest risk (incidence 11%).
All patients diagnosed with PE had symptoms of dyspnoea and/or chest pain, as did 65% without PE. All patients investigated for asymptomatic tachycardia or palpitations alone were negative for PE.
A normal ECG did not exclude PE (6/9 had normal ECG). Of those with PE, two had abnormal CXR(25%), compared with 20 in those without PE(23%).
Two women with PE had a history of VTE (20%). Three of four women diagnosed post-partum had caesarean section delivery. Other traditional risk factors (pregnancy loss, gestational diabetes, obesity, smoking) did not appear more prevalent in those with PE.
Conclusions
Despite our perceived low threshold for diagnostic scanning, this study demonstrated a higher incidence of PE than reported elsewhere. Similar to other studies, the post-partum period had the highest incidence of PE. Although overlapping clinical symptom and non-specific ancillary tests (ECG, CXR) support the need for VQ/CT-PA in many women, in this small study we did not see any women with asymptomatic tachycardia diagnosed with PE.