D-Dimer levels are known to be elevated in pregnancy. But how high is too high and can this test be used in the workup of VTE in pregnant patients?
Recent literature indicates that D-dimer levels in each of the three trimesters are approximately 39% higher: 700, 1000, and 1400 ng/dL for each trimester (normal cutoff 500 ng/dL). So, figure out what trimester your patient is in and use the corresponding D-Dimer level for that trimester.
References
Hernandez J, Hambleton G, Kline JA. D-dimer concentrations in normal pregnancy. Acad Emerg Med 2004;11:526-527
