(753) Impact of Intramuscular Oxytocin on Postpartum Hemorrhage During a National Intravenous Fluid Shortage

Oxytocin infusion requires dilution in intravenous (IV) fluids to reduce risk for toxicity. In response to the national IV fluid shortage in 2024, our hospital transitioned from a bolus of IV oxytocin (30 units in 500 mL lactated Ringer’s) to intramuscular (IM) oxytocin (10 units) for active management of the third stage. We aimed to evaluate the impact of the IM oxytocin protocol on postpartum hemorrhage (PPH) rates.

Study Design:

This is a retrospective cohort study of all vaginal deliveries ≥ 34 weeks at a quaternary hospital. We compared patients from the IM oxytocin period (10/2024-2/2025) to the same months during the two preceding years (IV oxytocin group; 10/2022-2/2023 and 10/2023-2/2024). The primary outcome was rate of PPH (blood loss ≥1000 mL). Secondary outcomes included total blood loss, additional uterotonic administration, and severe maternal morbidity. T-test, chi-square, and Wilcoxon rank-sum were used as appropriate. Logistic regression was performed for potential confounders.

Results:

Of 3963 patients, 1173 received IM oxytocin (30%) and 2790 received IV oxytocin (70%) postpartum. Patients who received IM oxytocin were more likely to have public insurance and receive prostaglandin labor augmentation; they were less likely to receive oxytocin augmentation or have admission thrombocytopenia (Table 1). Median total labor IV fluids were lower in the IM oxytocin group (661 mL vs 1816 mL, P< 0.01). PPH rates were lower in the IM oxytocin group (1% vs 2%, P=0.04), but not after adjusting for admission thrombocytopenia (aOR 0.5, 95% CI 0.3-1.0). Use of additional uterotonics and tranexamic acid were more common in the IM oxytocin group; however, transfusion, hysterectomy, ICU admission, and postpartum length of stay were similar (Table 2).

Conclusion:

Although adjusted analyses showed no significant difference in PPH, the IM oxytocin group required additional uterotonic administration. While IM oxytocin is a feasible alternative during an IV fluid shortage, its use may warrant closer clinical surveillance.