Replacement of oxytocin bolus administration by infusion: influences on postpartum outcome

Intramuscular versus intravenous oxytocin for the third stage of labor after vaginal delivery to prevent postpartum hemorrhage: a meta-analysis of randomized controlled trials

INTRODUCTION

To examine the effects and safety of oxytocin administered intramuscularly or intravenously for preventing postpartum hemorrhage (PPH) in the third stage of labor after vaginal deliveries.

MATERIAL AND METHODS

Before data extraction, the review was registered with the PROSPERO International Prospective Register of Systematic Reviews (registration No. CRD42019145912). We searched the published electronic databases, including Medline, EMBASE, PubMed, Web of Science, CNKI, VIP, Wanfang, the Cochrane Library, clinicaltrial.gov and PROSPERO database, from their inception until February 2019. We included all randomized controlled trials (RCTs) comparing intramuscular and intravenous oxytocin administered just after the birth of the anterior shoulder or soon after the birth of the baby during a vaginal delivery. The primary outcomes were the incidence of PPH and severe PPH. PPH was defined as a blood loss ≥500 ml within 24 hours after vaginal birth. Severe PPH refers to a clinically estimated blood loss equal to or greater than 1000 mL within 24 hours after vaginal birth. Statistical heterogeneity was assessed by the I² test, the Cochran Q statistic and the Galbraith plot for heterogeneity.

RESULTS

Six RCTs, including 7320 women undergoing vaginal delivery, were identified in the meta-analysis. Women who were randomized to have intravenous oxytocin for the third stage of labor had a significantly lower incidence of PPH (relative risk 1.35, 95% CI 1.11-1.64, p = 0.003), severe PPH (relative risk 1.61, 95% CI 1.05-2.46, p = 0.03) and blood transfusion (relative risk 2.50, 95% CI 1.37-4.59, p = 0.003) compared with those who were randomized to have intramuscular oxytocin during the third stage of labor after vaginal delivery. There was no significant difference with regard to changes in hemoglobin level, third stage of labor duration, mean postpartum blood loss, or the incidences of a need for additional uterotonics and of retained placenta or manual removal of placenta between groups.

CONCLUSIONS

For women in the third stage of labor who are undergoing a vaginal delivery, the use of intravenous oxytocin reduces the incidence of PPH, severe PPH and blood transfusion and does not increase the risk of adverse effects compared with intramuscular oxytocin.

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.