Aim: Pregnancy is a hypercoagulable state, however it remains unknown
the degree to which pregnancy affects standardly drawn coagulation laboratory
studies. We intended to establish reference intervals for D-dimer and fibrinogen
in the third trimester of pregnancy. Methods: We recruited 1048 healthy
Chinese pregnant women with low-risk pregnancy. Concentrations of D-dimer and
fibrinogen in the third trimester were collected. The 2.5th and 97.5th percentile
reference intervals of D-dimer and fibrinogen in pregnant women with parity = 1,
parity 2, maternal age 35 years, maternal age 35 years, PPH
and non-PPH were established during the third trimester of pregnancy.
Results: D-dimer levels were above the conventional cut-off point (0.5
mg/L) in 99.33% of pregnant women. Fibrinogen levels were above the normal
upper limit (4 g/L) in 63.93% of pregnant women. The reference interval of
D-dimer and fibrinogen in the third trimester of low-risk pregnant women was
0.63–5.05 mg/L and 3.02–5.92 g/L, respectively. Conclusion: The
concentration of D-dimer and fibrinogen in the blood during pregnancy differ from
the normal population. We recommend that the reference intervals be established
for Chinese healthy pregnant women.
