Abstract
Background
Increased clot permeability and susceptibility to lysis have been reported in women
with heavy menstrual bleeding. We hypothesized that similar alterations in fibrin
clot properties may also be present in women with postpartum hemorrhage (PPH) of unknown
cause.
Objective
To determine fibrin clot properties and their determinants in women after PPH of unknown
cause.
Methods
We studied 52 consecutive women, aged 35 years (27–40), after at least 3 months since
PPH of unknown cause and 52 matched controls for age, weight, and fibrinogen. Coagulation
factors (F), antithrombin, thrombin generation, along with a comprehensive plasma
fibrin clot analysis including fibrin polymerization, clot permeability (K
s), and fibrinolysis efficiency were determined.
Results
Women with PPH showed reduced activity of FII (−10.3%), FV (−6.6%), FIX (−6.5%), FX
(−7.2%), and FXI (−5.7%) compared with the controls, though all values were within
ranges (all p < 0.05). There were no intergroup differences in fibrinogen, FVIII, FXIII, and thrombin
generation. The PPH group formed with a delay looser plasma fibrin network (K
s; +16.3%, p = 0.008) with lower maximum absorbance and shorter clot lysis time (CLT; −13.5%,
p = 0.001) compared with the controls. On multivariable logistic regression, PPH was
independently associated with higher C-reactive protein (per 1 mg/L, odds ratio [OR] = 1.70,
95% confidence interval [CI]: 1.09–2.68), lower FII (per 1%, OR = 0.93, 95% CI: 0.89–0.98),
lower FV (per 1%, OR = 0.93, 95% CI: 0.89–0.97), and shorter CLT (per 1 minute, OR = 0.94,
95% CI: 0.90–0.98).
Conclusion
Prohemorrhagic fibrin clot properties, with lower, though normal coagulation factors,
characterize women with PPH of unknown cause, which suggests novel mechanisms contributing
to this type of bleeding.
Keywords
coagulation factors - fibrinolysis - fibrin clot - postpartum hemorrhage
