Thromboelastography in the second trimester of pregnancy in the prediction of adverse pregnancy outcome

Abstract

Thromboelastography (TEG) is a method of monitoring global homeostatic function as a dynamic process, involving the interaction between the protein coagulation cascade and platelets, as opposed to the isolated end points measured by conventional coagulation screens. The purpose of this study is to determine whether TEG variables can be used in the second trimester to predict the development of adverse pregnancy outcomes such as pre‐eclampsia and intrauterine growth restriction (IUGR defined as birth weight below the 5th centile for gestational age).Methods: A prospective study of a cohort of 273 pregnant women who underwent TEG assessment at 18–24 weeks gestation. Standard parameters were measured from each TEG tracing (R is the reaction time, K the clot formation time, A the angle, and MA the maximum amplitude). Pregnancy outcomes were obtained from the case notes of 251 participants. Twenty‐two patients were lost at follow up. The Mann–Whitney test was employed for analysis, as the above parameters did not follow normal distribution.Results: Twenty‐three pregnancies (9.2%) were complicated by IUGR and 10 (4%) by pre‐eclampsia. In the IUGR group, no significant difference was observed in any of the TEG parameters in comparison to the normal pregnancies (for R time: Mann–Whitney U = 2296, for K time: U = 2556, for MA: U = 2514.5, for A‐angle: U = 2433, 95% CI (1972, 3273)). Similarly, TEG parameters did not differ significantly in the pregnancies complicated by pre‐eclampsia (for R time: Mann–Whitney U = 971.5, for K time: U = 1063.5, for MA: U = 1199.5 and for A‐angle: U = 1183, 95% CI (765, 1646)). Comparisons after logarithmic transformation, did not reveal any significant differences between the two groups.Conclusion: Thromboelastography parameters in the second trimester of pregnancy did not differ in normally developed and complicated pregnancies. Therefore, they cannot be used as a single predictor of adverse pregnancy outcome. This is a pilot study, therefore, further studies are required to evaluate their use in conjunction with established predictive tests.