- Patho/Etiology
- A rare but life-threatening complication of the third trimester or early postpartum period.
- Caused by a defect in mitochondrial beta-oxidation of fatty acids.
- Strongly associated with fetal long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, an autosomal recessive disorder.
- Unmetabolized fetal fatty acids enter the maternal circulation, overwhelming the mother’s (often a heterozygous carrier) enzymatic capacity and leading to microvesicular fatty infiltration of hepatocytes.
- Clinical Presentation
- Insidious onset of nausea/vomiting, RUQ/epigastric pain, malaise, anorexia, and headache.
- Can rapidly progress to fulminant liver failure, presenting with jaundice, hepatic encephalopathy (e.g., confusion), and profound hypoglycemia.
- Patients may also present with polydipsia (excessive thirst) and polyuria.
- Diagnosis
- A clinical diagnosis based on presentation and lab findings; liver biopsy is the gold standard but rarely performed due to bleeding risk.
- Labs:
- Profound hypoglycemia is a hallmark feature.
- ↑↑ Bilirubin and ↑↑ Ammonia.
- Moderately elevated aminotransferases (AST/ALT usually < 500 IU/L).
- Coagulopathy: ↑ PT/PTT, ↓ fibrinogen, thrombocytopenia.
- Leukocytosis and elevated uric acid are common.
- Differential Diagnostics
- HELLP Syndrome: A major differential. Key features distinguishing AFLP from HELLP include:
- AFLP: More severe liver dysfunction (significant jaundice, hypoglycemia, coagulopathy, ↑ ammonia).
- HELLP: Dominated by Hemolysis (schistocytes), Elevated Liver enzymes, and severe Low Platelets. Hypertension is more common and severe in HELLP.
- Pre-eclampsia with severe features: Presents with HTN and proteinuria, but LFT elevation is typically milder.
- Viral Hepatitis: Presents with much more dramatic elevation of aminotransferases (AST/ALT often >1,000 IU/L).
- Management
- IMMEDIATE DELIVERY of the fetus is the only definitive treatment, regardless of gestational age.
- Aggressive supportive care in an ICU setting is critical.
- IV dextrose to correct hypoglycemia.
- Correction of coagulopathy with blood products like fresh frozen plasma (FFP) and cryoprecipitate.
- Monitoring and support for multi-organ failure (e.g., renal failure, pancreatitis).
- Liver transplantation is rarely needed but may be considered if liver function does not improve after delivery.
- Key Associations/Prognosis
- Risk factors include nulliparity, multiple gestations, and carrying a male fetus.
- Maternal and fetal mortality was once very high but has significantly improved with early diagnosis and prompt delivery.
- The infant should be screened for LCHAD deficiency post-delivery.
- The condition can recur in future pregnancies, with a genetic chance of 25%.