What to do for postpartum uterine atony (failure of the uterus to contract after delivery)?

Management of Postpartum Uterine Atony

Uterine atony should be managed immediately with uterine massage and oxytocin as first-line treatment, followed by second-line uterotonics if needed, and surgical interventions for refractory cases to prevent life-threatening hemorrhage. 1

Initial Management

• Uterine atony is the most common cause of postpartum hemorrhage (>75% of cases) and is typically a clinical diagnosis 1
• Begin with uterine massage to stimulate contractions 1
• Administer oxytocin as first-line treatment:
  • IV infusion: 10-40 units in 1000 mL of non-hydrating solution at a rate necessary to control atony 2
  • IM administration: 10 units after placental delivery 2
  • Initial IV bolus of 1-3 IU may be sufficient for elective cesarean deliveries, with higher doses needed for intrapartum cesarean deliveries 3

Second-Line Treatments

If uterine atony persists despite oxytocin and massage:

• Administer second-line uterotonic agents early when oxytocin fails 3:
  • Carboprost tromethamine (prostaglandin F2α): indicated for postpartum hemorrhage due to uterine atony that has not responded to conventional management including IV oxytocin, uterine massage, and ergot preparations 4
  • Methylergonovine: for routine management of uterine atony and hemorrhage 5, but is contraindicated in hypertensive patients due to risk of vasoconstriction 1
  • Consider intramyometrial injection of prostaglandins for severe cases unresponsive to other treatments 6

Advanced Interventions

For refractory uterine atony:

• Uterine tamponade using intrauterine balloons or packing 1, 3
• Surgical options if bleeding continues:
  • Bilateral uterine artery ligation 1
  • B-Lynch compression suture 1, 3
  • Hysterectomy for extreme cases unresponsive to other measures 1, 3

Special Considerations

• Thoroughly inspect the cervix and vagina to rule out lacerations that may contribute to bleeding 1
• For cesarean deliveries with diffuse bleeding not amenable to surgical control, consider packing the pelvis and transferring to ICU for further medical therapy 1
• In cases of massive hemorrhage, implement early aggressive resuscitation with blood products (packed red cells, fresh-frozen plasma, and platelets at a 1:1:1 ratio) 1
• Assess for coagulopathy, which may develop following cardiovascular collapse 1

Risk Factors to Consider

• Hispanic or non-Hispanic white ethnicity, preeclampsia, and chorioamnionitis are independent risk factors for uterine atony 7
• Other risk factors include obesity, labor induction/augmentation, multiple gestation, polyhydramnios, and prolonged second stage of labor 3, 7
• Advanced maternal age may require higher doses of oxytocin to prevent uterine atony 8

Common Pitfalls to Avoid

• Delaying administration of second-line uterotonics when oxytocin fails 3, 6
• Using methylergonovine in patients with hypertension (contraindicated due to risk of severe hypertension) 1
• Administering prostaglandins too late in management when excessive blood loss and shock have already developed 6
• Misdiagnosing amniotic fluid embolism based solely on hemorrhage from persistent atony with secondary coagulopathy 1

Remember that prompt recognition and aggressive management of uterine atony are essential to prevent maternal morbidity and mortality from postpartum hemorrhage 1, 3.