Evaluation of in vivo effects of Oxytocin on coagulation of parturient during cesarean delivery by thromboelastography

Objective: Oxytocin routinely used as an uterotonic drug in cesarean delivery. Clothing problems, adverse effects on fibrinogen and bleeding were presented as side effects of oxytocin. In in vivo investigation, modest hypercoagulable state was suggested as a side effect for infusion of oxytocin in parturients. In this study, effects of two different infusion rates of oxytocin on coagulation of parturient were evaluated during cesarean delivery. Methods: In a randomized double-blinded clinical trial, 84 healthy parturient in two equal groups took oxytocin infusion with the rate of 15 IU/h (Group A) or 30 IU/h (Group B), after the umbilical cord clamping. Coagulation status measured 30 min after beginning of infusion by thromboelastography. Data were analyzed by chi(2) , paired sample test and ANOVA considering as significant at P < 0.05. Findings: The mean (standard deviation) of variables in Groups A and B were 2.4024 (0.86) and 2.0429 (0.68) for K (kinetics of clot development), 55.4429 (11.30) and 60.7595 (10.41) for alpha (speed of clot strengthening) and 59.779 (19.15) and 70.61 (11.30) for maximum amplitude (maximum clot strength), respectively. The P values for these variables were 0.036, 0.028 and < 0.001, respectively; these changes are consistent with increasing coagulability. Other measures did not have significant differences. Conclusion: This in vivo investigation clarified that increasing infusion rate of oxytocin to 30 IU/h can augment coagulability in term parturients.