PURPOSE: Advances in maternal-fetal medicine have significantly decreased the incidence of maternal death secondary to eclampsia, hemorrhage, and infection. Venous thromboembolism (VTE) is now the leading cause of death in the obstetric population with an incidence of 0.1-0.2%. The diagnosis of VTE in pregnant patients is difficult secondary to changes in maternal physiology and lack of evidence-based diagnostic algorithm. Recent clinical trials have established the utility of D-dimer in low risk medical patients. These studies have typically excluded pregnant patients.
METHODS: The patient population consisted of pregnant females from outpatient offices and emergency room visits presenting with a possible diagnosis of VTE from 2004 to 2007. Radiology records were reviewed to find patients that had computed tomography of the thorax performed using a pulmonary embolism protocol and/or unilateral or bilateral lower extremity venous Doppler ultrasound performed. Any patient that also had a D-dimer test was included in the analysis. D-dimer testing was performed using the Vidas DD rapid enzyme immunoassay (Biomerieux, Mary Letoile, France).
RESULTS: Twenty-nine patients were identified. Three patients had positive radiographic studies for VTE with all three having D-dimer levels greater than 2500 (ng/ml). Using a cutoff of 1300 ng/ ml as normal for pregnant patients, we found a sensitivity of 100% and specificity of 27.3% for detection of VTE.
CONCLUSION: The utility of D-dimer is pregnancy remains undefined. Our retrospective review of a limited number of patients allows us to conclude that D-dimer may be able to provide significant diagnostic information in helping to rule-out VTE in low risk pregnant patients, but larger studies are indicated.
CLINICAL IMPLICATIONS: Current algorithms do not provide evidence regarding the utility of D-dimer testing in pregnant patients. This retrospective study provides support that D-dimer may be useful in objectively evaluating this unique patient population for venous thromboembolism. The use of D-dimer as a screening tool in pregnant patients needs further large-scale prospective studies to confirm our findings.
DISCLOSURE: Christopher Gilbert, No Financial Disclosure Information; No Product/Research Disclosure Information