Frequency of DIC as a Cause of Postpartum Hemorrhage
DIC is a relatively uncommon cause of postpartum hemorrhage, accounting for a small minority of cases, while uterine atony remains the dominant etiology at over 75% of PPH cases. 1, 2
Primary Causes of PPH
The causes of PPH follow a clear hierarchy in frequency:
- Uterine atony is the most common cause, responsible for more than 75% of all PPH cases 2
- Trauma (lacerations, rupture, hematomas) represents the second most common category 1
- Retained products of conception (RPOC) with or without infection 1
- Coagulopathy (including DIC) is listed among the "less common causes" of PPH 1
DIC as a Secondary Complication
DIC more commonly develops as a consequence of severe PPH rather than as a primary cause. 3, 4 The relationship is bidirectional:
- Massive hemorrhage can trigger DIC through consumption of coagulation factors and platelets 5, 4
- Pre-existing obstetric conditions that cause DIC (placental abruption, amniotic fluid embolism, HELLP syndrome, retained stillbirth, acute fatty liver of pregnancy) may then lead to hemorrhage 3, 4
- DIC is recognized as a leading cause of maternal death when it occurs, despite being relatively uncommon 5, 4
Clinical Recognition Challenges
The diagnosis of DIC is often delayed until uncontrollable bleeding or multi-organ failure has developed, representing scenarios that may be unsalvageable 4. Key diagnostic considerations include:
- Standard coagulation tests (PT, PTT, fibrinogen, platelets, D-dimer) must be interpreted in the context of pregnancy-specific reference ranges 1, 4
- A pregnancy-specific DIC score (≥26 points) using fibrinogen, PT difference, and platelet count has 88% sensitivity and 96% specificity 4
- Fibrinogen <2 g/L occurs in 17% of cases with blood loss exceeding 2000 mL, indicating evolving coagulopathy 6
Management Implications
When DIC complicates PPH, the clinical approach differs significantly:
- Immediate correction of coagulopathy with blood products (packed RBCs, fresh frozen plasma, platelets, fibrinogen concentrate) is essential 5, 7, 8
- Damage control surgery with pelvic packing may be necessary to allow time for coagulation correction 5, 8
- All 10 cases in one series with DIC and severe PPH required hysterectomy (4 subtotal, 6 total), with 5 requiring relaparotomy and pelvic packing 8
Critical Pitfall
Do not wait for laboratory confirmation of DIC before initiating massive transfusion protocol when blood loss exceeds 1,500 mL 2, 9. The clinical presentation of ongoing hemorrhage unresponsive to uterotonic therapy should trigger immediate blood product administration in fixed ratios while addressing the underlying cause 2, 6.