What are the possible causes of postpartum splenomegaly?

Postpartum Splenomegaly: Etiologies

Life-Threatening Causes Requiring Immediate Exclusion

Cirrhosis with portal hypertension must be ruled out immediately, as splenic artery aneurysm rupture in this setting carries 70-95% maternal mortality, particularly in the early postpartum period. 1

• Splenic artery aneurysm rupture represents the highest mortality risk (70-95%) and typically occurs in the third trimester or early postpartum in women with cirrhosis and severe splenomegaly, presenting with abdominal pain, syncope, and hemorrhagic shock. 1
• Budd-Chiari syndrome should be considered, particularly in women with known vascular liver disease or thrombophilia, as it causes hepatosplenomegaly through hepatic venous outflow obstruction. 1
• The first 1-6 days postpartum represent the highest risk period for morbidity and mortality from hypertensive complications and hemorrhage. 1

Portal Hypertension-Related Causes

Portal hypertension from any cause is the most common mechanism of splenomegaly in the postpartum period:

• Cirrhosis with portal hypertension is a common cause of splenomegaly, often associated with thrombocytopenia and other signs of portal hypertension. 2, 3
• Non-cirrhotic portal hypertension can cause significant splenomegaly and was present in 2 of 5 pregnant women with massive splenomegaly in one case series. 4
• Wilson disease may present with isolated splenomegaly due to clinically inapparent cirrhosis with portal hypertension. 2, 3
• Hypersplenism is common in patients with advanced cirrhosis and is multifactorial, linked to portal hypertension with intra-splenic sequestration. 5
• After transplantation, portal pressure decreases rapidly, but in the presence of pre-transplant splenomegaly, subclinical hypersplenism may persist in some patients. 5

Infectious Causes

Infectious etiologies are among the most common causes of splenomegaly globally:

• Chronic malaria was identified as the cause in 1 of 5 pregnant women with massive splenomegaly in a case series. 4
• Parasitic infections, such as malaria and schistosomiasis, are common causes of splenomegaly in tropical regions. 3
• Endocarditis can lead to splenic abscess and splenomegaly. 2

Hematologic Disorders

Hematologic malignancies and disorders can present with or worsen splenomegaly in the postpartum period:

• Myeloproliferative disorders, particularly myelofibrosis, are associated with massive splenomegaly. 2
• Polycythemia vera and essential thrombocythemia should be considered, with progression to post-PV or post-ET myelofibrosis defined by increasing splenomegaly ≥5 cm from left costal margin. 3
• Hairy cell leukemia characteristically presents with splenomegaly. 3
• Hemophagocytic lymphohistiocytosis (HLH) is an aggressive syndrome of excessive immune activation that can present with splenomegaly. 6

Autoimmune and Inflammatory Disorders

• Autoimmune disorders, including rheumatoid arthritis with Felty syndrome, can cause splenomegaly. 2, 3
• Systemic lupus erythematosus (SLE) may present with splenomegaly. 3

Metabolic Storage Disorders

While less common in acute postpartum presentation, storage disorders should be considered in unexplained cases:

• Lysosomal storage diseases commonly present with both hepatomegaly and splenomegaly, including Niemann-Pick disease, Gaucher disease, acid sphingomyelinase deficiency (ASMD), and lysosomal acid lipase deficiency (LALD). 2, 3
• Glycogen storage diseases (GSDs) frequently present with hepatomegaly, with some types also causing splenomegaly. 2

Cardiac Causes

• Congestive cardiac failure can cause splenomegaly. 6
• Peripartum cardiomyopathy (PPCM) most frequently presents during the first few days postpartum with heart failure and marked fluid retention, which could theoretically contribute to splenic congestion. 5

Critical Clinical Pitfall

Never assume hepatosplenomegaly is physiologic in the postpartum period—it always requires investigation. 1 The American Association for the Study of Liver Diseases emphasizes that postpartum hepatosplenomegaly mandates immediate hepatology referral, as early intervention can prevent progression of liver fibrosis. 1