RESUMO
Objective The objective of this study was to determine the optimal dose of intravenous oxytocin administered during cesarean delivery (CD) to decrease the amount of blood loss. Methods Out of a total of 226 women presenting for CD, 189 patients were randomized into three groups by a computer-generated random number sequence table. Low-risk women with singleton term pregnancies undergoing scheduled CD were assigned to receive 20, 30, or 40 units (U) of oxytocin diluted in 500 mL of lactated Ringer solution intraoperatively. The primary outcome was the change in hemoglobin from pre-CD to post-CD. Results Overall, 63 women were assigned to each group. The primary outcome which was the drop in hemoglobin (1.4 ± 1.1 g/dL, 1.1 ± 0.8 g/dL, 1.0 ± 1.1 g/dL; p = 0.097) and the total calculated blood loss (798.6 ± 298.3 mL, 794.4 ± 313.5 mL, 820.2 ± 316.2 mL; p = 0.893) were not significantly different among the study groups. The incidence of intraoperative hypotension, postoperative systolic, and diastolic blood pressure changes was similar across the groups. Conclusion The amount of blood loss during CD was not significantly different among the three groups, thus the lowest dose of oxytocin infusion (20 U in 500 mL of lactated Ringer solution) seems to be an appropriate regimen.