BACKGROUND AND PURPOSE:

• Masse et al. (Obstetrics and Gynecology, 2022) evaluated whether the administration of prophylactic methylergonovine in addition to oxytocin in patients undergoing intrapartum cesarean birth reduces the need for additional uterotonic agents

METHODS:

• Single-center, placebo-controlled, randomized trial
• Participants
  • Patients undergoing intrapartum cesarean birth
• Interventions
  • Study group: Intervention: IV oxytocin (300 mL/minute) and IM methylergonovine 0.2 mg (1 mL)
  • Control: IV oxytocin (300 mL/minute) and IM saline (1 mL)
• Study design
  • Sample size of 76 patients per group
  • Goal to detect a twofold decrease in the need for additional uterotonic agents based upon a 42% baseline
  • 80% power | Two-sided type 1 error of 5%
• Primary outcome
  • Receipt of additional uterotonic agents
• Secondary outcomes
  • Surgeon assessment of uterine tone
  • Incidence of postpartum hemorrhage (>1 L within the first 24 hours postpartum)
  • Quantitative blood loss
  • Blood transfusion

RESULTS:

• Intervention: 80 patients | Control: 80 patients
• Significantly fewer patients who were allocated to the methylergonovine group received additional uterotonic agents
  • Intervention: 20%
  • Control: 55%
  • Relative risk (RR) 0.4 (95% CI, 0.2 to 0.6)
• Participants receiving methylergonovine were also more likely to have
  • Satisfactory uterine tone
    • Intervention: 80%
    • Control: 41%
    • RR 1.9 (95% CI, 1.5 to 2.6)
  • Lower incidence of postpartum hemorrhage
    • Intervention: 35%
    •  Control: 59%
    • RR 0.6 (95% CI, 0.4 to 0.9)
  • Lower mean quantitative blood loss
    • Intervention: 967 mL
    • Control: 1315 mL
    • Mean difference 348 (95% CI, 124 to 572)
  • Lower frequency of blood transfusion
    • Intervention: 5%
    • Control: 23%
    • RR 0.2 (95% CI, 0.1 to 0.6)

CONCLUSION:

• In the setting of intrapartum cesarean delivery, adding prophylactic methylergonovine to oxytocin significantly reduced the need for additional uterotonic agents
• The authors state

Prior studies have noted oxytocin resistance in laboring patients undergoing intrapartum cesarean birth

Continuous exposure of human myometrial cells to oxytocin leads to a loss in their capacity to respond to oxytocin

The administration of prophylactic methylergonovine in patients requiring intrapartum cesarean birth could therefore serve to improve uterine tone and decrease postpartum hemorrhage by facilitating uterine contraction through an alternative, non–oxytocin receptor–dependent pathway

Learn More – Primary Sources:

Prophylactic Methylergonovine and Oxytocin Compared With Oxytocin Alone in Patients Undergoing Intrapartum Cesarean Birth: A Randomized Controlled Trial

Related ObG Topics:

RCT Results: Does the Addition of Uterotonics to Prophylactic Oxytocin Reduce PPH following Cesarean for Arrest of Labor

Cochrane Review 2018: Uterotonic Agents for PPH Prophylaxis

Meta-Analysis: Comparison of Medications for PPH Prevention During Cesarean Delivery

Postpartum Hemorrhage – Medications to Treat Uterine Atony