A female patient collapses soon after delivery. There is profuse bleeding and features of disseminated intravascular coagulation. Which of the following is the most likely etiology?

Correct Answer: A. Amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare but catastrophic obstetric emergency characterized by the entry of amniotic fluid into the maternal circulation, triggering a biphasic pathophysiological response. The discriminating feature here is the combination of acute collapse immediately after delivery with profuse bleeding and DIC — this constellation is pathognomonic for AFE.

AFE causes DIC through two mechanisms: (1) direct activation of the extrinsic coagulation cascade by tissue factor present in amniotic fluid, and (2) release of thromboplastic substances from fetal cells. The profuse bleeding results from consumption of platelets and clotting factors during DIC, leading to a consumptive coagulopathy. The acute cardiovascular collapse occurs due to pulmonary embolism from amniotic fluid material and release of vasoactive mediators (serotonin, histamine, prostaglandins) that cause pulmonary hypertension, right ventricular failure, and systemic hypotension.

AFE typically occurs during labor, delivery, or immediately postpartum (as in this case), with an incidence of 1 in 40,000 deliveries in India. Risk factors include operative deliveries, placental abruption, and uterine trauma. The mortality rate remains high (10–15% even with treatment), and survivors often suffer neurological sequelae. Management is supportive: aggressive fluid resuscitation, blood product transfusion (FFP, platelets, RBC), vasopressors, and treatment of DIC with cryoprecipitate and platelets as per coagulation profile.

Why the other options are wrong

B. Rupture of the uterus — Uterine rupture causes profuse bleeding and hypovolemic shock, but does NOT cause DIC. DIC is the hallmark discriminator here. Uterine rupture presents with acute abdominal pain, loss of fetal heart sounds, and vaginal bleeding, but the coagulation cascade is not activated by uterine tissue alone. This is the NBE trap — both cause hemorrhage, but only AFE causes DIC. C. Uterine prolapse — Uterine prolapse is a mechanical complication where the uterus inverts and protrudes through the vagina, typically occurring immediately after delivery of the placenta. It causes hemorrhage and shock but does NOT trigger DIC. Prolapse is managed by manual reduction and oxytocin, not coagulation support. This option is a distractor for students who focus only on 'postpartum hemorrhage.' D. Peripartum cardiomyopathy — Peripartum cardiomyopathy (PPCM) causes acute heart failure and cardiogenic shock in the peripartum period, but it does NOT cause DIC or profuse bleeding. PPCM presents with dyspnea, orthopnea, and pulmonary edema, not hemorrhage. While both AFE and PPCM cause acute cardiovascular collapse, only AFE triggers the thromboplastic cascade leading to DIC and consumptive coagulopathy.

High-Yield Facts

Mnemonics

AFE = Amniotic Fluid Embolism triad Acute collapse + Fibrinolysis (DIC) + Embolism (pulmonary). Remember: AFE = Acute + Fibrin consumption + Embolism. Use when you see postpartum collapse + DIC together. DIC in AFE (not in other postpartum hemorrhages) Tissue factor in amniotic fluid → Hypercoagulability → Rapid consumption → Outcome = DIC. Only AFE has the thromboplastic trigger; uterine rupture and prolapse cause bleeding without DIC.

NBE Trap

NBE pairs "postpartum hemorrhage" with multiple obstetric emergencies (uterine rupture, prolapse, AFE) to trap students who focus only on bleeding. The discriminator is DIC — only AFE causes consumptive coagulopathy due to tissue factor in amniotic fluid. Students who choose uterine rupture or prolapse miss this pathognomonic feature.

Clinical Pearl

In Indian obstetric practice, AFE is often missed in the immediate postpartum period because it mimics hemorrhagic shock. The key bedside clue is the sudden onset of DIC with normal or only mildly elevated bleeding — if a postpartum patient crashes with severe coagulopathy out of proportion to blood loss, think AFE first. Early recognition and aggressive FFP + platelet transfusion can be life-saving.

_Reference: DC Dutta's Textbook of Obstetrics (3rd ed), Ch. 23 (Complications of Labour); Harrison's Principles of Internal Medicine, Ch. 297 (Obstetric Complications)_