From the Guidelines
For the prevention of postpartum hemorrhage, the recommended oxytocin concentration is 5 to 10 IU, administered slow IV or intramuscular infusion, at the time of shoulder release or immediate postpartum. This recommendation is based on the most recent guidelines for the management of urgent obstetric situations in emergency medicine, published in 2022 1. The administration of oxytocin at this dosage and timing is crucial in reducing the incidence of postpartum hemorrhage, which is a leading cause of maternal mortality worldwide.
Key Considerations
- Oxytocin should be administered slow IV or intramuscular infusion to avoid rapid IV bolus, which can cause hypotension, tachycardia, and other cardiovascular effects.
- The dosage of 5 to 10 IU is recommended, as it is effective in stimulating the smooth muscle of the uterus to contract, compressing blood vessels and reducing bleeding at the placental site.
- Monitoring is important during administration, as side effects may include nausea, vomiting, headache, and rarely, water intoxication with prolonged infusion.
Clinical Context
The prevention of postpartum hemorrhage is critical in reducing maternal morbidity and mortality. Uterine atony is the most common cause of early postpartum hemorrhage, and oxytocin is highly effective in treating this condition 1. Therefore, the administration of oxytocin at the recommended dosage and timing is essential in clinical practice.
From the FDA Drug Label
To control postpartum bleeding, 10 to 40 units of oxytocin may be added to 1,000 mL of a nonhydrating diluent and run at a rate necessary to control uterine atony The oxytocin concentration for prevention of postpartum hemorrhage is 10 to 40 units per 1000 mL of nonhydrating diluent.
- The rate of infusion should be adjusted to control uterine atony 2.
- Intramuscular administration is also an option, with a dose of 10 units given after delivery of the placenta.
From the Research
Oxytocin Concentration for Prevention of Postpartum Hemorrhage
- The World Health Organization recommends 10 IU of intramuscular or intravenous oxytocin for preventing postpartum hemorrhage 3.
- Oxytocin is the first-line uterotonic agent in the United States for prevention of postpartum hemorrhage, with evidence strong for its use 4.
- Carbetocin, a long-acting analog of oxytocin, is likely the most effective single pharmacologic therapy for prevention of postpartum hemorrhage, but it is not yet available for use in the United States 4.
- Combined therapy with oxytocin and other uterotonics, such as methylergonovine, misoprostol, and carboprost, has an additive or synergistic effect and a greater risk reduction for postpartum hemorrhage prevention compared with oxytocin alone 4.
Comparison of Uterotonic Agents
- A network meta-analysis found that ergometrine plus oxytocin and misoprostol plus oxytocin were the highest-ranked agents for preventing postpartum hemorrhage, with ergometrine plus oxytocin reducing the risk of postpartum hemorrhage ≥ 500 mL compared with oxytocin alone (RR 0.76,95% CI 0.64 to 0.90, high-certainty evidence) 3.
- Carbetocin, injectable prostaglandins, and ergometrine have similar effects compared with oxytocin, while misoprostol may be less effective in preventing postpartum hemorrhage ≥ 1000 mL compared with oxytocin (RR 1.24,95% CI 1.06 to 1.46, low-certainty evidence) 3.
- Oxytocin is more effective than misoprostol for prevention and treatment of uterine atony and has fewer adverse effects 5.
Administration Strategies
- Oxytocin administration strategies, such as initiating as a bolus, may have a higher probability of being the best uterotonic for reducing blood loss and the need for additional uterotonics 6.
- Carbetocin is probably the most effective agent in reducing blood loss and the need for additional uterotonics, and oxytocin appears to be more effective when initiated as a bolus 6.
Guidelines and Recommendations
- The American College of Obstetricians and Gynecologists, the Royal College of Obstetricians and Gynecologists, and other medical societies recommend uterine massage, bimanual uterine compression, and administration of uterotonics, including oxytocin, for the management of postpartum hemorrhage due to uterine atony 7.
- Active management of the third stage of labor, including the administration of oxytocin, is recommended for the prevention of postpartum hemorrhage 7.