D-Dimer levels at different stages of pregnancy in Australian women: a single centre study using two different immunoturbidimetric assays.
BACKGROUND
To date there is minimal data available on D-Dimer levels at different stages of pregnancy.


METHODS
We prospectively measured D-Dimer levels in 632 consecutive pregnant women from March 2007 to January 2009. The median age of the participants was 31 years (range; 18-42) with a median weight of 78 kilograms (range; 46-137). All subjects were investigated during each trimester with two different immunoturbidimetric assays; D-Dimer PLUS and INNOVANCE D-Dimer. D-Dimer levels were determined using a Sysmex® CA 1500 analyser.


RESULTS
Our data demonstrate that D-Dimer levels in pregnancy show different patterns of rise within the first trimester, depending on the assay used; D-Dimer PLUS=0.88 (SD: mean ratio), INNOVANCE D-Dimer=0.72 (SD: mean ratio). Furthermore, the rise in mean results was greater for the INNOVANCE D-Dimer assay compared to the D-Dimer PLUS assay as shown by the ratio of third to first trimester results of 3.68 and 1.96 respectively. Both D-Dimer assays demonstrated moderate levels of intra-subject variability, with overall mean CVs of 16.5% (D-Dimer PLUS) and 16.9% (INNOVANCE D-Dimer). Furthermore, we studied the association between D-Dimer levels and occurrence of diseases of pregnancy. For both assays, there was no consistently interpretable evidence of an association between raised mean D-Dimer levels or rising D-Dimer levels and any of the diseases or conditions associated with pregnancy.


CONCLUSIONS
Our data suggest that the INNOVANCE D-Dimer assay increases significantly with the advancement of pregnancy, and is more sensitive than D-Dimer PLUS assay in the pregnant population.
Launceston General Hospital (LGH) Tasmania, Australia. Khalafallah@dhhs.tas.gov.au
Alhossain A
AA
Khalafallah
Michael
M
Morse
Abdul-Majeed
AM
Al-Barzan
Murray
M
Adams
Amanda
A
Dennis
Gerald
G
Bates
Iain
I
Robertson
David
D
Seaton
Terry
T
Brain
D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D001774:Blood Chemical Analysis / Q000706:statistics & numerical data; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data*; D009391:Nephelometry and Turbidimetry / Q000379:methods* / Q000706:statistics & numerical data*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000097:blood* / Q000453:epidemiology*; D011264:Pregnancy Trimesters; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D