Increased coagulation index as measured by Thromboelastography during ovarian stimulation for in vitro fertilization: Influence of the final oocyte maturation triggering agent

Objective: Thromboelastography (TEG) is a viscoelastic test of hemostasis which allows measurement of the processes of clot initiation, propagation, stabilization, and dissolution in real time. In this study we aimed to evaluate the alterations in coagulation as measured by TEG during In Vitro Fertilization (IVF) stimulation cycles and to investigate whether final oocyte maturation with recombinant hCG (rhCG) versus GnRH agonist results in a different coagulation state.

Study design: This is a prospective observational study which included fifty-three normogonadotrophic women. All the patients received an antagonist IVF treatment protocol. Final oocyte maturation was triggered with either rhCG (n = 25) or GnRH agonist (n = 26). Two patients did not complete the study due to poor response. Venous blood was drawn in the early and late follicular phase and on the day of ovum pickup. The TEG parameters assessed were R (time to first clot formation), K (time until the clot reaches a fixed strength), alpha angle (the rate of clot formation), MA (reflects maximum strength of the platelet-fibrin clot), LY30 (percent of clot lysis at 30 min after MA is reached) and the CI (the overall coagulability).

Results: The overall coagulation index of the entire study population was significantly increased on the day of ovum pickup as compared to the early follicular phase. This increase in the coagulation index was also significant in a subanalysis of patients triggered with rhCG. Contrarily, there was no significant increase in the coagulation index in the subgroup of patients triggered with GnRH agonist.

Conclusion: Our results demonstrate a procoagulable state in patients after ovulation induction. Final triggering with GnRH agonist rather than rhCG, might lower this hypercoagulability pattern.