Background and Aims Thromboelastogram (TEG) gives information about the coagulation cascade showing the combined effects of coagulation factors and thrombocyte functions. Thrombin Generation Assay (TGA) measures the time dependent changes of thrombin concentration. Standard values for newborns do not exist for TGA and TEG. We aimed to evaluate the effects of prematurity and vitamin K on hemostatis by TEG and TGA in addition to conventional methods.

Methods Preterm (n=16) and term (n=36) infants who received routine vitamin K prophylaxis were evaluated with pt, inr, ptt, fibrinogen, TEG and TGA measurements performed from cord blood and venous blood obtained on day 3.

Results Cord blood pt, inr, ptt and fibrinogen values were similar in both groups. TEG-R value was increased in preterm group showing delayed onset of coagulation compared to term group (p=0.003). Other TEG and TGA measurements were similar in cord blood.

After vitamin K prophylaxis; pt and inr decreased, fibrinogen increased in preterm infants (p values; 0.032, 0.01 and 0.009, respectively). In term infants; ptt decreased, fibrinogen, TEG-R, TEG-MA and TGA-lag time increased after vitamin K (p values; 0.034, 0.001, < 0.001, 0.018, < 0.001 and 0.004, respectively).

Conclusion In cord blood analyses; preterm infants didn’t have a significant difference apart from a delay in coagulation. The cloth strength was increased in term infants after vitamin K. The lack of such improvement in preterm infants may be attributable to immature hepatic functions of the preterms. Preliminary data for standard values of TEG and TGA were obtained.