Pulmonary Embolism Post-Delivery: Yes, It Is Possible and Represents a Critical Risk Period
Yes, pulmonary embolism can absolutely occur after delivery, and the postpartum period—particularly the first 4 weeks—represents the highest risk time for this life-threatening complication. 1, 2
Incidence and Timing
The rate of postpartum pulmonary embolism is 0.45 per 1000 births, making it a rare but serious complication that requires vigilance. 2
Approximately half of severe postpartum pulmonary embolisms occur within the first 24 hours after delivery, with risk remaining elevated throughout the first 4 weeks postpartum before approaching baseline population rates. 2, 3
Pulmonary embolism is more common after cesarean section compared to vaginal delivery, though the absolute risk following cesarean birth has been declining despite rising cesarean rates. 2, 4
Why the Postpartum Period Is High-Risk
Pregnancy and the postpartum period create a hypercoagulable state that dramatically increases venous thromboembolism risk compared to non-pregnant women. 2, 5
The European Society of Cardiology explicitly addresses PE management "during pregnancy or shortly after delivery," recognizing this as a distinct high-risk period requiring specific protocols. 1
Strongest Risk Factors for Postpartum PE
The following factors most strongly predict postpartum pulmonary embolism:
- Stillbirth (adjusted odds ratio = 5.97) 2
- Lupus (adjusted odds ratio = 8.83) 2
- Transfusion of coagulation products (adjusted odds ratio = 8.84) 2
- Cesarean delivery (particularly emergency cesarean) 2, 4
- Obesity 5
Clinical Presentation Challenges
Most signs and symptoms of PE are non-specific in the postpartum period, making diagnosis challenging and requiring a high index of suspicion. 5, 6
Formal diagnostic assessment with validated methods is mandatory (Class I recommendation) if PE is suspected during the postpartum period, as delayed diagnosis can be fatal. 1, 7
Diagnostic workup should begin with D-dimer measurement and clinical prediction rules (Class IIa recommendation), though approximately 50% of women have normal D-dimer at 20 weeks gestation. 1, 8
Severity and Mortality
Pulmonary embolism remains one of the leading causes of direct maternal death in high-income countries, with a mortality rate of 0.56 deaths per 100,000 deliveries. 1
In cases of severe PE during pregnancy and up to 6 weeks postpartum, 23% of women experienced cardiac arrest, highlighting the catastrophic potential of this complication. 1
Case fatality rates range from 13-19% when PE occurs in the peripartum period. 1
Treatment Considerations Specific to Postpartum PE
Immediate therapeutic anticoagulation with LMWH or UFH is the cornerstone of treatment, with the choice depending on hemodynamic stability and bleeding risk. 9, 7
Critical Timing Issues After Delivery:
For women who had epidural/spinal anesthesia, LMWH cannot be given for ≥4 hours after epidural catheter removal, and therapeutic doses require waiting 24 hours after the neuraxial block. 9, 7
The risk of major bleeding with thrombolysis is dramatically higher in the postpartum period (58%) compared to during pregnancy (18%), making alternative interventions (catheter thrombectomy, surgical embolectomy, ECMO) preferable when available for massive PE. 3
For High-Risk PE with Hemodynamic Instability:
Thrombolysis should be considered for life-threatening PE, though the bleeding risk postpartum is substantial. Maternal survival with thrombolysis is 94%, but major bleeding occurs in 58% of postpartum cases. 1, 3
Surgical embolectomy is a viable option even after sustained cardiac arrest, with reported maternal survival of 86%. 3, 4
Duration of Anticoagulation
Anticoagulation must be continued for ≥6 weeks after delivery with a minimum overall treatment duration of 3 months. 1, 7
LMWH and warfarin can be given to breastfeeding mothers; NOACs are contraindicated. 1, 7
Common Pitfalls to Avoid
Never dismiss non-specific symptoms (dyspnea, chest pain, syncope) in the postpartum period, as PE diagnosis is primarily clinical and symptoms overlap with normal postpartum recovery. 5, 6
Never delay anticoagulation while awaiting diagnostic confirmation in patients with high or intermediate clinical probability of PE. 9
Never administer regional anesthesia within 24 hours of therapeutic LMWH, as this risks catastrophic spinal hematoma. 9, 7
Do not confuse amniotic fluid embolism with thrombotic PE—amniotic fluid embolism occurs during labor or immediately after delivery with sudden cardiovascular collapse and disseminated intravascular coagulation, requiring entirely supportive management rather than anticoagulation. 1, 7