Hypercoagulability in pregnant trauma patients

Circulating hormones affect coagulopathy in pregnancy and after trauma. The hemostatic profile of pregnant women after injury has not been characterized. We hypothesized that injured pregnant females would present with an initial thrombelastography (TEG) reflecting a more hypercoagulable profile and a higher incidence of venous thromboembolic events (VTE) when compared with non-pregnant females and males.

Methods: Cohort study of adult trauma patients with TEG measured on arrival was performed from 2009 to 2018 with data extracted from medical records. Nearest-neighbor matching was used to match each pregnant patient by age, Injury Severity Score, prehospital transfusion, and arrival Glasgow Coma Scale with non-pregnant females and males, each in a maximum 1:4 ratio. Hypercoagulable profiles were defined as alpha (α) angle ≥76° and maximum amplitude (MA) ≥65 mm. Lysis at 30 minutes after MA (LY-30) was considered high if ≥3.0% and low if ≤0.8%. Univariate and multivariable analyses were performed.

Results: Seventy-six pregnant trauma patients were matched to 301 non-pregnant females and 301 males. Demographics were similar between groups, except pregnant females more frequently suffered blunt trauma. Pregnant females presented with a higher α angle, high MA and lower LY-30 than both control groups. Pregnant females met hypercoagulable criteria and had a low LY-30 more frequently than non-pregnant females and males. No pregnant patient versus 2% in each control group developed VTE. Transfusion requirements in the first 24 hours after admission and mortality were similar between groups. After adjustment, low MA and high LY-30 were associated with increased odds of mortality, regardless of sex or pregnancy. Hypocoagulable α angle was associated with pregnancy complications.

Conclusion: Injured pregnant females frequently presented with a profile that would be considered hypercoagulable under normal reference ranges. However, given the absence of VTE events, this profile may be non-pathologic.

Level of evidence: IV.