acute fatty liver of pregnancy (AFLP)

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Acute fatty liver of pregnancy (AFLP) is a rare pregnancy-associated condition that tends to manifest in the 3 trimester of pregnancy or early postpartum period.

Epidemiology

The estimated incidence is at around 1:7000-20,000 births.

Clinical presentation

Patients may present with nausea, vomiting, right upper quadrant pain, and/or jaundice.

Pathology

The pathogenesis may be related to an abnormality in fetal fatty acid metabolism.

Associations

pre-eclampsia

Diagnostic criteria

According to the Swansea criteria for the diagnosis of acute fatty liver of pregnancy, six or more of the following findings are required in the absence of another cause :

vomiting
abdominal pain
polydipsia/polyuria
encephalopathy
elevated bilirubin > 14 µmol/l
hypoglycemia < 4 mmol/l
elevated urea > 340 µmol/l
leukocytosis > 11 x 10⁹ /l
ascites or bright liver on ultrasound scan
elevated transaminases (AAT or ALT) > 42 IU/l
elevated ammonia > 47 µmol/l
renal impairment: creatinine > 150 µmol/l
coagulopathy: prothrombin time > 14 seconds or APPT > 34 seconds
microvesicular steatosis on liver biopsy

Radiographic features

Imaging features are often that of fatty infiltration of the liver.

Ultrasound

Non-specific findings are usual and the liver can even be normal in echotexture . However, in the context of biliary type symptoms, ultrasound may be useful to rule out other causes of obstructive biliary tract pathology.

CT

May show evidence of low attenuation which is again non-specific.

Treatment and prognosis

mortality is ~20%, with the cause of death usually due to sepsis, renal failure, circulatory collapse, pancreatitis or gastrointestinal bleeding
liver function tests may show a continued deterioration for up to one week postpartum in the surviving patients and then the values slowly recover