What is the diagnosis for a woman in labor who develops sudden dyspnea, hypotension, and Disseminated Intravascular Coagulation (DIC)?

Amniotic Fluid Embolism

The diagnosis is amniotic fluid embolism (AFE), a rare but catastrophic obstetric emergency characterized by the classic triad of sudden hypoxia, hypotension, and subsequent coagulopathy occurring in relation to labor and delivery. 1

Clinical Diagnosis

AFE remains a clinical diagnosis of exclusion based on the presence of the characteristic triad and ruling out other causes of sudden cardiovascular collapse. 1 No specific diagnostic laboratory test can confirm or refute the diagnosis at the bedside. 1

Classic Presentation

The clinical presentation in this case is textbook AFE:

• Sudden dyspnea - representing acute respiratory failure with severe hypoxemia from pulmonary vasoconstriction and mechanical obstruction 1
• Hypotension - reflecting cardiovascular collapse from right ventricular failure and hemodynamic instability 1
• DIC - occurring either immediately with or following the cardiopulmonary collapse 1

Pathophysiology

The condition follows a biphasic pattern:

• Phase 1 (Early): Acute right ventricular failure from increased pulmonary vascular resistance due to mechanical obstruction by fetal cellular debris and pulmonary vasoconstriction 1, 2
• Phase 2 (Late): Left ventricular failure with cardiogenic pulmonary edema and systemic hypotension 1

The coagulopathy results from amniotic fluid activating Factor VII and platelets, triggering DIC, with the inflammatory response further activating the clotting cascade. 1

Differential Diagnosis to Exclude

While AFE is the most likely diagnosis given this presentation, other conditions must be rapidly considered:

• Pulmonary embolism - unlikely with profuse bleeding/DIC present 1
• Myocardial infarction - would require cardiac troponins and ECG 1
• High spinal anesthesia - causes apnea but not dramatic cardiac output drop or hemorrhage 1
• Sepsis - typically more gradual onset 1
• Eclampsia - would have seizures and hypertension history 1

The rapid appearance of DIC is the clinical finding that ultimately confirms AFE diagnosis. 1

Timing and Context

AFE occurs most commonly:

• 70% during labor 1, 2
• 11% after vaginal delivery 1, 2
• 19% during cesarean delivery 1, 2

The condition can rarely occur during first or second trimester pregnancy termination or amniocentesis. 1

Critical Management Priorities

Immediate multidisciplinary activation is essential - notify anesthesiology, maternal-fetal medicine, critical care, and neonatology. 1

Key Initial Actions:

• High-quality CPR with ACLS protocols if cardiac arrest occurs 1
• Activate massive transfusion protocol immediately - anticipate severe hemorrhage from DIC and uterine atony 1
• Avoid excessive fluid resuscitation - risk of worsening pulmonary edema 1
• Consider norepinephrine for blood pressure support 1
• Bedside echocardiography to confirm right ventricular failure 1

Common Pitfall

Do not misdiagnose primary postpartum hemorrhage with secondary coagulopathy as AFE. Bleeding from uncontrolled uterine atony followed by hypovolemic shock and consumptive/dilutional coagulopathy is NOT amniotic fluid embolism. 1 True AFE presents with the cardiopulmonary collapse FIRST, followed by coagulopathy, not the reverse. 1

Prognosis

Despite optimal management, AFE carries significant maternal and perinatal morbidity and mortality, with an average case-fatality rate of approximately 16%. 3 However, outcomes have improved with advances in critical care recognition and aggressive early intervention. 2