Intramuscular injection, intravenous infusion, and intravenous bolus of oxytocin in the third stage of labor for prevention of postpartum hemorrhage: a three-arm randomized control trial.

BACKGROUND

Oxytocin for postpartum hemorrhage (PPH) prophylaxis is commonly administered by either intramuscular (IM) injection or intravenous (IV) infusion with both routes recommended equally and little discussion of potential differences between the two. This trial assesses the effectiveness and safety of 10 IU oxytocin administered as IM injection versus IV infusion and IV bolus during the third stage of labor for PPH prophylaxis.

METHODS

In two tertiary level Egyptian maternity hospitals, women delivering vaginally without exposure to pre-delivery uterotonics were randomized to one of three prophylactic oxytocin administration groups after delivery of the baby. Blood loss was measured 1 h after delivery, and side effects were recorded. Primary outcomes were mean postpartum blood loss and proportion of women with postpartum blood loss ≥500 ml in this open-label, three-arm, parallel, randomized controlled trial.

RESULTS

Four thousand nine hundred thirteen eligible, consenting women were randomized. Compared to IM injection, mean blood loss was 5.9% less in the IV infusion arm (95% CI: -8.5, - 3.3) and 11.1% less in the IV bolus arm (95% CI: -14.7, - 7.8). Risk of postpartum blood loss ≥500 ml in the IV infusion arm was significantly less compared to IM injection (0.8% vs. 1.5%, RR = 0.50, 95% CI: 0.27, 0.91). No side effects were reported in any arm.

CONCLUSIONS

Intravenous oxytocin is more effective than intramuscular injection for the prevention of PPH in the third stage of labor. Oxytocin delivered by IV bolus presents no safety concerns after vaginal delivery and should be considered a safe option for PPH prophylaxis.

TRIAL REGISTRATION

clinicaltrials.gov # NCT01914419 , posted August 2, 2013.