Active Management of Third Stage of Labor to Prevent PPH in Women with History of Macrosomic Deliveries
Oxytocin Administration Protocol
Administer 5–10 IU oxytocin by slow intravenous infusion (over 1–2 minutes) or 10 IU intramuscularly immediately after delivery of the anterior shoulder (or immediately after complete infant delivery) and before placental delivery. 1
Timing and Route
Give oxytocin at the moment the anterior shoulder is delivered—do not wait until after placental expulsion. 1 This timing is critical for effectiveness in preventing uterine atony, which is the primary mechanism of PPH in women with macrosomic deliveries.
For intravenous administration: infuse 5–10 IU over 1–2 minutes as a slow bolus. 1 Rapid IV push (faster than 1 minute) causes hypotension and tachycardia and must be avoided. 1
For intramuscular administration: give 10 IU IM. 1, 2 This route is equally effective and preferred when IV access is unavailable or unreliable. 1
Rationale for This Population
Women with a history of multiple macrosomic deliveries face substantially elevated PPH risk due to uterine overdistension, which impairs myometrial contractility after delivery. 3 Birth weight >4000g is one of the most significant risk factors for postpartum hemorrhage. 3 Active management with immediate oxytocin prophylaxis reduces PPH incidence by approximately 60% compared to expectant management. 4, 5
Additional Components of Active Management
Delayed Cord Clamping
- Delay cord clamping for 1–3 minutes after birth to allow placental transfusion. 1 This benefits neonatal hematological outcomes without increasing maternal blood loss when combined with immediate oxytocin administration. 1
Controlled Cord Traction
- Apply controlled cord traction for placental delivery only after signs of placental separation appear and the uterus is contracted. 4 Routine aggressive traction without these signs increases risk of uterine inversion and should be avoided. 4
Avoid Routine Interventions That Do Not Reduce PPH
Do not perform routine sustained uterine massage after placental delivery. 1 Evidence does not support this as a universal requirement, though gentle massage to assess tone is appropriate. 1
Do not perform manual removal of the placenta routinely to reduce PPH risk. 1 This should only be done in cases of severe and uncontrollable hemorrhage or retained placenta beyond 30 minutes with active bleeding. 1
Medications to Avoid in This Setting
Ergometrine Contraindications
Do not use ergometrine (methylergonovine) as first-line prophylaxis. 1 Although ergot alkaloids may reduce blood loss, they carry higher risk of severe hypertension, increased need for manual placental removal, and bronchospasm—especially in patients with respiratory comorbidities. 1, 5
Ergometrine is absolutely contraindicated in patients with hypertension. 1 Many women with macrosomic deliveries have underlying gestational diabetes or chronic hypertension, making ergometrine particularly hazardous in this population.
Prostaglandin Precautions
- Avoid prostaglandin F₂α in any patient with a history of asthma or reactive airway disease. 1 It can provoke severe bronchoconstriction. 1
Rescue Interventions if PPH Occurs Despite Prophylaxis
Tranexamic Acid
If PPH develops despite prophylactic oxytocin, administer tranexamic acid 1 g IV within 1–3 hours of bleeding onset. 1 Efficacy decreases by 10% for every 15 minutes of delay, so early administration is critical. 1
Tranexamic acid reduces bleeding-related maternal mortality when given early in the course of PPH. 1 The WOMAN trial demonstrated this benefit specifically within the first 3 hours. 1
Additional Uterotonics
If uterine atony persists after initial oxytocin, administer additional uterotonic agents per institutional protocol. 4, 6 Second-line options include:
Women with prior exposure to exogenous oxytocin during labor require higher oxytocin infusion rates (ED90 of 44.2 IU/h vs 16.2 IU/h in non-laboring women) to achieve adequate uterine tone. 7 This is relevant if the patient labored before delivery.
Intrauterine Tamponade
- Consider intrauterine balloon tamponade if pharmacologic measures fail and before proceeding to surgery or interventional radiology. 4 This can be life-saving and uterus-sparing in refractory atony. 4
Critical Pitfalls to Avoid
Do not delay oxytocin administration until after the placenta is delivered—timing immediately after shoulder delivery is essential for efficacy. 1
Do not give oxytocin as a rapid IV bolus (faster than 1–2 minutes). 1 This causes acute hypotension, tachycardia, and potential cardiovascular collapse. 1
Do not use ergometrine in patients with hypertension or respiratory disease. 1 The vasoconstriction and bronchospasm risks outweigh any benefit. 1
Do not postpone tranexamic acid if bleeding continues—every 15-minute delay reduces effectiveness by 10%. 1
Establish early IV access during labor for women with BMI ≥30 or other high-risk features (including history of macrosomia). 1 This ensures immediate vascular access if PPH occurs. 1
Summary Algorithm for This Patient
- At delivery of anterior shoulder: Give oxytocin 5–10 IU slow IV (over 1–2 min) or 10 IU IM 1
- After infant delivery: Delay cord clamping 1–3 minutes 1
- After placental separation: Apply controlled cord traction 4
- Assess uterine tone: Gentle palpation to confirm contraction 1
- If PPH occurs: Tranexamic acid 1 g IV immediately + additional uterotonics 1, 4
- If atony persists: Intrauterine balloon tamponade 4
- Avoid: Ergometrine, rapid oxytocin bolus, routine manual removal 1
This approach prioritizes oxytocin as the gold-standard first-line agent, recognizes the specific hemorrhage risk in macrosomic deliveries, and provides a clear escalation pathway if bleeding occurs despite prophylaxis.