Objective: To compare the effect of intraumbilical vein oxytocin injection with standard management in reducing blood loss during the third and fourth stages of labor. Acute complications threaten the mother’s life during the third and fourth stages of labor. The most common complication is postpartum hemorrhage, which remains a leading cause of maternal mortality, particularly in developing countries. Methods: A randomized controlled trial was conducted in the Gynecology and Obstetrics Department of Leonardo Martínez Valenzuela Hospital from January to June 2021. A probabilistic sample was used: 332 pregnant patients were enrolled in the study and randomized into the case (166 patients) and control (166 patients) groups. The volume of blood lost was compared between the groups. Results: The median estimated blood loss was 120 mL (interquartile range [IQR], 80-218.75 mL). There was a statistically significant difference between the groups, showing less estimated blood loss in the international unit group with a median of 80 mL (IQR, 60-100 mL) (P<0.001), and 200 mL (IQR, 143.75-300 mL) in the intramuscular (IM) group, highlighting that 66.8% of the IM group had an estimated blood loss >251 mL. Conclusion Any reduction in bleeding during labor is clinically relevant because it improves patient prognosis. The use of intraumbilical oxytocin injection with active management of the third stage of labor significantly reduced postpartum blood loss and the duration of the third stage compared with the IM group.