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

BJOG. 2019 Feb;126(3):383-392. doi: 10.1111/1471-0528.15286. Epub 2018 Jun 14.


Objective: To identify clinical features associated with pulmonary embolism (PE) diagnosis and determine the accuracy of decision rules and D-dimer for diagnosing suspected PE in pregnant/postpartum women DESIGN: Observational cohort study augmented with additional cases.

Setting: Emergency departments and maternity units at eleven prospectively recruiting sites and maternity units in the United Kingdom Obstetric Surveillance System (UKOSS) POPULATION: 324 pregnant/postpartum women with suspected PE and 198 pregnant/postpartum women with diagnosed PE METHODS: We recorded clinical features, elements of clinical decision rules, D-dimer measurements, imaging results, treatments and adverse outcomes up to 30 days MAIN OUTCOME MEASURES: Women were classified as having PE on the basis of imaging, treatment and adverse outcomes by assessors blind to clinical features and D-dimer. Primary analysis was limited to women with conclusive imaging to avoid work-up bias. Secondary analyses included women with clinically diagnosed or ruled out PE.

Results: The only clinical features associated with PE on multivariate analysis were age (odds ratio 1.06; 95% confidence interval 1.01-1.11), previous thrombosis (3.07; 1.05-8.99), family history of thrombosis (0.35; 0.14-0.90), temperature (2.22; 1.26-3.91), systolic blood pressure (0.96; 0.93-0.99), oxygen saturation (0.87; 0.78-0.97) and PE-related chest x-ray abnormality (13.4; 1.39-130.2). Clinical decision rules had areas under the receiver-operator characteristic curve ranging from 0.577 to 0.732 and no clinically useful threshold for decision-making. 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 threshold.

Conclusions: Clinical decision rules and D-dimer should not be used to select pregnant or postpartum women with suspected PE for further investigation. Clinical features and chest x-ray appearances may have counter-intuitive associations with PE in this context.

Tweetable abstract: Clinical decision rules and D-dimer are not helpful for diagnosing pregnant/postpartum women with suspected PE.

Keywords: Clinical decision rule; D-dimer; postpartum; pregnancy; pulmonary embolism.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Age Factors
  • Area Under Curve
  • Blood Pressure
  • Body Temperature
  • Cohort Studies
  • Decision Support Techniques*
  • Female
  • Fibrin Fibrinogen Degradation Products / metabolism*
  • Humans
  • Logistic Models
  • Multivariate Analysis
  • Odds Ratio
  • Oximetry
  • Pregnancy
  • Pregnancy Complications, Cardiovascular / diagnosis*
  • Pregnancy Complications, Cardiovascular / diagnostic imaging
  • Pregnancy Complications, Cardiovascular / metabolism
  • Puerperal Disorders / diagnosis*
  • Puerperal Disorders / diagnostic imaging
  • Puerperal Disorders / metabolism
  • Pulmonary Embolism / diagnosis*
  • Pulmonary Embolism / diagnostic imaging
  • Pulmonary Embolism / metabolism
  • ROC Curve
  • Radiography, Thoracic
  • Sensitivity and Specificity
  • United Kingdom


  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D