(842) Thromboelastography Values in Healthy Pregnant Individuals Compared to the Non-Pregnant Population

Objective:
Thromboelastography (TEG) is a method for assessing clotting and fibrinolysis that allows for real-time assessment of a patient’s coagulative status; based on the non-obstetric population. The obstetric population faces unique risks of hemorrhage requiring blood product replacement in which a TEG would be helpful in guiding management. The objective of this study is to understand the pregnancy-specific values for TEG parameters and directly compare these values to reference values in the non-pregnant population.

Study Design:
Data were synthesized from a prospective, cross-sectional study of healthy pregnant individuals, in which TEG was performed at various gestational time points and postpartum. After collection, we calculated the mean and 95% confidence intervals for TEG values (Reaction time (R), Clot Kinetics (K), Clot Angle (angle), Maximum amplitude (MA), Percent lysis at 30 minutes (Ly30), and functional fibrinogen). We utilized the Wilcoxon Sign Rank Test to compare the calculated means to the established TEG reference values for non-pregnant individuals.

Results:
Compared to non-pregnant individuals, pregnancy is associated with a marked hypercoagulable shift in TEG parameters. Specifically, R and K times are significantly lower (e.g., R: 4.69–5.05 min vs. 5.0–10.0 min, p=< 0.0001; K: 1.18–1.29 min vs. 1.0–3.0 min, p=< 0.0001). Angle and MA are increased (Angle: 70.53-72.38° vs. 53.00–72.00°, p=< 0.0001; MA: 68.90-70.65mm vs. 50.00–70.00mm, p=< 0.0001). Fibrinolysis (Ly30) is reduced in pregnancy. The pregnant individual’s point estimates are consistently located at the extremes of the literature’s confidence intervals.

Conclusion:
Our findings suggest evidence of hypercoagulable state in pregnant individuals with statistical differences in TEG parameters R, K, Angle, MA, LY30, and functional fibrinogen compared to the non-pregnant state. These findings suggest that pregnant individuals are afforded a hypercoagulable protective state, which should be considered in the setting of assessing coagulative status and blood product transfusion during pregnancy.