Acute fatty liver of pregnancy

Background

Inferior view of the liver with surface showing lobes and impressions.

• Rare, potentially fatal complication that presents in second half of pregnancy or (less commonly) early postpartum
• Exact etiology unclear, but thought to involve abnormal fetal fatty acid metabolism
• Fat vesicles accumulate within hepatocytes, interfering with liver function

Clinical Features

• Usually presents in 3rd trimester, but may occur any time in 2nd half of pregnancy to early postpartum
• Nausea/vomiting (commonly severe)
• Jaundice
• Findings consistent with preeclampsia in some women:
  • Hypertension
  • Edema
  • Proteinuria
• Hypoglycemia
• Often, signs/symptoms of DIC
• +/- encephalopathy, ascites

Differential Diagnosis

3rd Trimester/Postpartum Emergencies

• Acute fatty liver of pregnancy
• Amniotic fluid embolus
• Chorioamnionitis
• Eclampsia
• HELLP syndrome
• Mastitis
• Peripartum cardiomyopathy
• Postpartum endometritis (postpartum PID)
• Postpartum headache
• Postpartum hemorrhage
• Preeclampsia
• Resuscitative hysterotomy
• Retained products of conception
• Septic abortion
• Uterine rupture

Jaundice

Differential diagnosis of hyperbilirubinemia.

Indirect Hyperbilirubinemia

• Hemolytic
  • G6PD
  • Drug related
  • Autoimmune hemolytic anemia
• Hematoma resorption
• Ineffective erythropoiesis
• Gilbert's

Direct (Conjugated) Hyperbilirubinemia

• Choledocholithiasis
• Cholecystitis
• Ascending cholangitis
• AIDS cholangiopathy
• Stricture
• Neoplasm
  • Pancreatic head
  • Gallbladder
  • Primary liver (e.g. hepatocellular carcinoma)
  • Metastatic
• Obstructing AAA

Hepatocellular damage

Patient will have severely elevated AST/ALT with often normal Alkaline Phosphatase

• Viral hepatitis
• Fulminant hepatic failure
• alcoholic hepatitis
• Ischemic hepatitis
• Toxins
  • Isoniazid
  • Phenytoin
  • acetaminophen
  • Ritonavir
  • Halothane
  • Sulfonamide
• Autoimmune hepatitis
  • Primary biliary cirrhosis
• HELLP Syndrome
• Congestive Hepatopathy
  • CHF
  • Sepsis (Shock Liver)

Pregnancy Related

• HELLP syndrome
• Acute fatty liver of pregnancy
• Hyperemesis gravidarum
• Cholestasis of pregnancy

Transplant Related

• Transplant rejection
• Graft-vs-host disease

Pediatric Related

• Inborn error of metabolism
• Neonatal jaundice (physiologic)

Additional Differential Diagnosis

• Reye syndrome
• TPN
• Heatstroke
• Budd-Chiari (with acute ascites)
• Wilson's disease
• Sarcoidosis
• Amyloidosis

Masqueraders

Only bilirubin stains the sclera

• Carotenemia
• Quinacrine ingestion
• Dinitrophenol, teryl (explosive chemicals)

Evaluation

Workup

• LFTs
  • ALT/AST usually in 300-500 range, alk phos usually elevated in pregnancy
  • Hyperbilirubinemia- more pronounced than in preeclampsia
• BMP
  • Hypoglycemia
• DIC labs
  • Low fibrinogen, coagulopathy
  • DIC present in as many as 70% of patients
• CBC
  • Often shows leukocytosis
• UA
  • Proteinuria
• RUQ US
  • Non-specific; the liver can even be normal in echotexture
  • Useful to rule out other causes of obstructive biliary tract pathology.

Diagnosis

• Often initially misdiagnosed as preeclampsia/HELLP
  • Hypoglycemia, jaundice, ascites, hypofibrinogenemia all more common in AFLP

Swansea criteria<

At least six of the following findings, in the absence of another cause:ref>Dey M, Reema K. Acute Fatty liver of pregnancy. N Am J Med Sci. 2012;4 (11): 611-2. doi:10.4103/1947-2714.103339</ref>

• Vomiting
• Abdominal pain
• Polydipsia/polyuria
• Encephalopathy
• Elevated bilirubin
• Hypoglycemia
• Elevated urea
• Leukocytosis
• Ascites or bright liver on ultrasound scan
• Elevated transaminases (AAT or ALT)
• Elevated ammonia
• Renal impairment: elevated creatinine
• Coagulopathy: elevated prothrombin time or PT
• Microvesicular steatosis on liver biopsy

Management

• Emergent Ob/Gyn consult
  • Delivery typically results in rapid hepatic recovery
• Dextrose for hypoglycemia
• FFP, cryoprecipitate, and/or platelets for coagulopathy (see DIC)

Disposition

• Admit ICU or transfer to center with Ob