PB0456 - Evaluation of thrombin generation test parameters in pregnant women with preeclampsia: systematic review

Background: Preeclampsia (PE) has an idiopathic etiology, but presents with a pro-thrombotic state. The thrombin generation test (TGT) has been used to investigate hemostatic disorders in several clinical conditions including PE.

Aims: To evaluate whether the pattern and magnitude of hemostatic changes observed through TGT differ in pregnant women with PE compared to normotensive pregnant women.

Methods: A systematic search was carried out in the PubMed, LILACS, Web of Science and Embase databases, in November 2023, without restrictions on year and language. Observational studies were included that evaluated TGT parameters (Lag-time, Time to Peak, Peak, Endogenous Thrombin Potential - ETP) in pregnant women with mild, severe, early or late onset PE and in healthy pregnant women matched according to gestational age. The methodological quality of the studies was assessed using the adapted Newcastle-Ottawa Scale (NOS) and the Analytical Cross Sectional Studies Checklist.

Results: Of 2,329 articles retrieved, only 7 were included in this review (Figure 1), totaling 581 healthy pregnant women and 321 pregnant women with PE. When the data were analyzed globally, already at the beginning of pregnancy, ETP and Peak were significantly higher, and the Lagtime and Time to Peak were shorter in pregnant women with PE, compared to healthy pregnant women. However, pregnant women with severe PE had a significantly lower ETP and Peak and a longer Lagtime than pregnant women with mild PE. Furthermore, in early-onset PE, coagulation activation occurs earlier than in late-onset PE.

Conclusion(s): The findings reinforce a state of hypercoagulability in PE as a whole, but interestingly, it is attenuated in the most severe cases. Greater activation of the coagulation cascade occurs in the early stages of pregnancy before the clinical manifestation of the disease, which may give TGT a clinical perspective.
Financial support: CAPES, CNPq and FAPEMIG - Brazil.