D-dimer testing in pregnant patients: towards determining the next 'level' in the diagnosis of deep vein thrombosis

J Thromb Haemost. 2010 May;8(5):1004-11. doi: 10.1111/j.1538-7836.2010.03783.x. Epub 2010 Jan 30.


Summary background: The role of D-dimer in excluding deep vein thrombosis (DVT) in pregnancy is currently uncertain. We hypothesized that the specificity of sensitive D-dimer assays could be improved without compromising sensitivity by using higher D-dimer cut-off values.

Objective: To determine the test characteristics of two rapid enzyme-linked immunosorbent assays and three latex agglutination assays in pregnancy.

Method: We recruited consecutive pregnant women who presented to participating centers with suspected DVT for the study. Symptomatic women were investigated with compression ultrasonography, and received 3 months of clinical follow-up to assess for the presence of venous thrombosis. Plasma samples for D-dimer were collected and frozen at the time of presentation. The median and mean D-dimer values for respective trimesters of pregnancy in patients with and without DVT were calculated. Receiver operating curves (ROCs) were plotted for respective assays to establish the best cut-points. The test characteristics corresponding to standard cut-points and these 'pregnancy' cut-points are presented.

Results: The prevalence of DVT in our cohort was 6.6% (95% confidence interval 4.0-10.6%). The mean and median D-dimer values were significantly increased throughout pregnancy. Overall, women with confirmed DVT had higher D-dimer levels than women without DVT (P < 0.0001). Improved specificities (62-79%) were observed with the use of higher cut-points obtained from ROCs for all five assays, and high sensitivities were maintained (80-100%) for DVT diagnosis.

Conclusion: Using higher cut-points than those used in non-pregnant patients, the specificity of D-dimer assays for the diagnosis of DVT in pregnancy can be improved without compromising sensitivity. Validation in prospective management studies is needed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Enzyme-Linked Immunosorbent Assay
  • Fibrin Fibrinogen Degradation Products / analysis*
  • Humans
  • Limit of Detection
  • ROC Curve
  • Venous Thrombosis / diagnosis*


  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D