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Use of D-dimer and YEARS algorithm in pregnancy to rule out diagnosis of PE and avoid radiation imaging

Three Part Question

In [pregnant wome suspceted of Pulmonary embolus (PE)] can [d-dimer and standard clinical decision rules] be used to [rule out the diagnosis of PE and avoid need for radiation imaging]

Clinical Scenario

A 38- year-old woman presents to the Emergency Department (ED) in her third trimester of pregnancy. She complains of right sided chest pain and shortness of breath. There are no clinical signs of deep vein thrombosis (DVT) and she does not report haemoptysis. This is her second pregnancy and she has no personal or familial risk factors for PE. Her oxygen saturators are 98% with respiratory rate of 21 and a regular heart rate of 109 at rest. Her blood pressure is normal and she is afebrile. A junior doctor has already assessed the patient. He tells you that all the blood tests are normal except for a D-dimer which is raised at 625ng/mL. A chest X-ray (CXR) is clear and electrocardiograph (ECG) shows sinus rhythm. The junior doctor is unsure what to do next. He does not want to misdiagnose PE but is also worried about requesting CTPA.

Search Strategy

Online search was conducted in January 2021 via online library access at Manchester Metropolitan University using EBSCOhost platform. The platform enabled a selection of multiple databases including MEDLINE, AMED - The Allied and Complementary Medicine Database, OpenDissertations, CINAHL, eBook Collection (EBSCOhost), Education Abstracts (H.W. Wilson). The search terms entered were as follows: (“pregnancy or pregnant”) and (“pulmonary embolism or pulmonary thromboembolism”) and (“d-dimer and pulmonary embolism”) and (“ct or computed tomography or ct scan or cat scan or tomography or x-ray computed”) and (“imaging or radiography or radiology or diagnosis or diagnose”)
The search was restricted to papers available within the last 10 years. Search of The Cochrane Central Register of Controlled Trials (CENTRAL) returned 108 results of which none were to the question posed in this paper. BestBets search revealed 2 article, one of which remains incomplete and neither of which are pertinent to this assignment.

Search Outcome

A total of 62 articles were found. After individually reviewing the titles, abstracts and available full texts. Large proportion of papers were not primary research and did not address the outcomes related to the study question. Only 7 research papers were assessed as relevant.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Righini et al
France and Switzerland
395 patients 1st trimester 83 (21.0%) 2nd trimester 170 (43.0%) 3rd 142 (35.9%) Prospective diagnostic Multicentre Multinational 11 centres over 8 years low and intermediate pre-test probability n=392 Negative D-dimer 46/392 (11.7%) Positive D-dimer 341/392 (87%) 5/392 no D-dimer testSingle D-dimer cut off (<500ng/ml) unmodified revised Geneva score not validated in pregnancy (other variables such as age >65, surgery and cancer would not be applicable here)
VTE events during 3 months follow up(0%) of 46 (95% CI 0-8%)
D-dimer levels and pregnancy trimesters Negative D-dimer decreased with increasing gestation age {First Trimester 21/83 (25.3%) Second trimester 19/170 (11.1%) Third trimester 6/142 (4.2%)]
pre-test PE probability Low n=192 (48.6%) Intermediate n=200 (50.6%) High n=3 (0.8%
PE excluded n=367 Negative CTPA (n=290) Negative D-dimer and low PTP (n=46) Negative VQ (n=17)
Goodacre et al
Prospective cases-324 pregnant women with suspected PE Retrospective cases-198 pregnant and postpartum with PE diagnosed 32% in 1st and 2nd trinester 64% in 3rd and postpartum Observational cohort with retrospective cases 18 months over 11 centres (Emergency departments and Maternity units)D-dimer sensitivity and specificity Sensitivities and specificities of D-dimer were 88.4% and 8.8% using a standard threshold and 69.8% and 32.8% using a pregnancy-specific thresholddifferent hospitals use different assays and diagnostic end points 73% patients received anticoagulation prior to blood sampling
confirmation of PE198 pregnant/postpartum (retrospective) (n= 161 (81%) on imaging) (n= 2 on post mortem) (n=35 on clinical diagnosis) (n=44 (22%) had D-dimer test)
clinical features associated with PEThe only clinical features associated with PE on multivariate analysis were age (odds ratio 1.06; 95% confidence interval 1.01-1.11


  1. Righini M, Robert-Ebadi H, Elias A, et al CT-PE pregnancy group Diagnosis of Pulmonary Embolism During Pregnancy: a multi centre prospective management outcome study Annals of Internal Medicine 169 (11):766-773
  2. Goodacre S, Horspool K, Nelson-Piercy C. et al The DiPEP study: an observational study of the diagnostic accuracy of clinical assessment, D-dimer and chest X-ray for suspected pulmonary embolism in pregnancy and postpartum International Journal of Obstetrics and Gynaecology