What are the causes of ascites in women?

Causes of Ascites in Women

Primary Etiologies

Cirrhosis accounts for 75-85% of all ascites cases in women, with the remaining 15-20% caused by malignancy, heart failure, tuberculosis, and nephrotic syndrome. 1

Portal Hypertension-Related Causes (SAAG ≥1.1 g/dL)

Hepatic causes:

• Cirrhosis is the dominant etiology, with alcoholic liver disease being highly reversible—abstinence yields 75% 3-year survival versus 0% if drinking continues 1, 2
• Nonalcoholic steatohepatitis should be considered in women with obesity 1
• Hepatitis B can respond dramatically to antiviral therapy 1
• Autoimmune hepatitis is another cirrhotic cause 1

Cardiac causes:

• Heart failure produces ascites distinguishable by elevated jugular venous distention (absent in cirrhosis) and markedly elevated pro-brain natriuretic peptide levels (median 6100 pg/mL in heart failure versus 166 pg/mL in cirrhosis) 1

Vascular causes:

• Budd-Chiari syndrome and sinusoidal obstruction syndrome cause portal hypertension through hepatic venous outflow obstruction 1

Non-Portal Hypertension Causes (SAAG <1.1 g/dL)

Malignant causes:

• Peritoneal carcinomatosis accounts for 9-10% of all ascites cases, most commonly from breast, colon, gastric, or pancreatic primaries in women 1
• Cytology sensitivity reaches 96.7% if three 50-mL samples are hand-carried fresh and warm to the lab for immediate processing 1

Infectious causes:

• Tuberculous peritonitis occurs in 10-12% of cases, particularly in recent immigrants from endemic areas or those with HIV/AIDS 1
• Fluid culture sensitivity is only 50%, smear sensitivity approximately 0%, making laparoscopy with biopsy and mycobacterial culture of tubercles the gold standard 1
• Adenosine deaminase cut-off of 27-32 U/L provides 91.7-100% sensitivity and 92-93.3% specificity for tuberculous peritonitis 1

Other causes:

• Nephrotic syndrome causes ascites through hypoalbuminemia 1
• Pancreatic ascites from pancreatitis shows markedly elevated ascitic amylase (typically >1000 mg/dL) 1

Mixed Ascites

Approximately 5% of women with ascites have two or more simultaneous causes, usually cirrhosis plus peritoneal carcinomatosis or tuberculosis 1, 3. Many patients with enigmatic ascites eventually have 2-3 causes identified (e.g., heart failure, diabetic nephropathy, and cirrhosis from nonalcoholic steatohepatitis) 4.

Critical Female-Specific Considerations

Never order serum CA-125 in any woman with ascites—it is elevated in all patients with ascites from any cause and leads to unnecessary surgery and death. 1 Gynecologic causes should only be considered when appropriate clinical context exists, not based on elevated CA-125 alone 1.

Diagnostic Algorithm

Step 1: Perform diagnostic paracentesis on all new-onset ascites 1, 3

• Mandatory initial tests: cell count with differential, total protein, albumin 1
• Calculate SAAG by subtracting ascitic fluid albumin from serum albumin (obtained same day) 4

Step 2: Interpret SAAG with 97% accuracy 4, 1

• SAAG ≥1.1 g/dL = portal hypertension (cirrhosis, heart failure, Budd-Chiari)
• SAAG <1.1 g/dL = non-portal hypertension (malignancy, tuberculosis, pancreatitis, nephrotic syndrome)

Step 3: Order additional tests based on SAAG and clinical suspicion 1

• If malignancy suspected: cytology (three 50-mL samples processed immediately)
• If infection suspected: culture in blood culture bottles at bedside
• If tuberculosis suspected: adenosine deaminase (cut-off 27-32 U/L)
• If pancreatic ascites suspected: ascitic amylase
• If heart failure suspected: pro-brain natriuretic peptide

Prognostic Implications

Development of ascites marks severe clinical deterioration, with 5-year survival dropping from 80% to 30% in cirrhosis 3. Approximately 15% of patients die within 1 year and 44% within 5 years 1. All women developing ascites should be evaluated for liver transplantation. 1

Common Pitfalls

Avoid these errors:

• Ordering CA-125 in women with ascites leads to misdiagnosis of ovarian cancer and unnecessary surgery 1
• Relying on fluid culture alone for tuberculous peritonitis misses 50% of cases—use adenosine deaminase or laparoscopy 1
• Assuming single etiology when 5% have mixed causes 1
• Paracentesis is safe even with severe coagulopathy (INR ≈8.7) or thrombocytopenia (platelets ≈19,000/µL), with bleeding risk only 0.2-2.2% 1