Towards evidence based emergency medicine: Best BETs from the Manchester Royal Infirmary. BET 2: Current evidence does support the use of a negative D-dimer to rule out suspected pulmonary embolism in pregnancy.

A short cut review was carried out to establish whether a negative D-dimer could be used to rule out pulmonary embolism in the presence of clinical suspicion in a pregnant patient. Five studies were considered directly relevant to the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes and study weaknesses were tabulated. The clinical bottom line was that a negative D-dimer result was considered sensitive enough to rule out pulmonary embolism in patients who were in the first two trimesters of pregnancy but that the false positive rate was so high as to render the test useless in patients in the third trimester if standard cut-off values were used.