Is a CT scan of the abdomen recommended in a suspected case of acute fatty liver of pregnancy with a differential diagnosis of HELLP (Hemolysis, Elevated Liver enzymes, and Low Platelet count) syndrome post-cesarean section (LSCS) without pregnancy-induced hypertension (PIH)?

CT Scan in Suspected AFLP vs HELLP Post-LSCS

Abdominal imaging should be performed in suspected HELLP syndrome to rule out hepatic hemorrhage, infarct, or rupture, but ultrasound is the preferred initial modality in pregnancy, with CT or MRI reserved for cases where ultrasound is inadequate. 1

Imaging Recommendations Based on Clinical Scenario

Initial Imaging Approach

• Ultrasound is the imaging modality of choice for initial evaluation of liver abnormalities in pregnancy due to lack of ionizing radiation and absence of known fetal risks, even in the postpartum period. 1
• Doppler interrogation of hepatic vasculature can be safely conducted but exposure time should be minimized. 1

When CT is Indicated

CT abdomen should be performed in the following specific situations:

• Suspected hepatic hemorrhage, infarct, or rupture in HELLP syndrome, particularly when the patient has severe epigastric pain or right upper quadrant pain that persists or worsens postpartum. 1, 2
• When ultrasound findings are inadequate or inconclusive for detecting serious hepatic complications. 1
• CT findings in HELLP-related hepatic complications include geographically wedge-shaped areas of low attenuation with mottled appearance indicating hepatic infarction. 2

Radiation Considerations Post-Delivery

• The fetal radiation concerns are no longer relevant post-LSCS, making CT a more acceptable option than during pregnancy. 1
• The currently accepted cumulative dose of ionizing radiation to the fetus during pregnancy is less than 50 mGy, but this restriction does not apply postpartum. 1

Differentiating AFLP from HELLP: Key Clinical Features

Laboratory Distinctions

Critical distinguishing features that guide imaging decisions:

• AFLP is characterized by: prolonged PT, reduced fibrinogen, hypoglycemia (<72 mg/dL), elevated ammonia, and hepatic encephalopathy if present. 3, 4
• HELLP syndrome features: hemolysis, elevated liver enzymes, thrombocytopenia, with 85% having hypertension (though your patient lacks PIH). 1, 4
• Antithrombin activity <65% is exclusively associated with AFLP and helps differentiate from HELLP. 4
• Approximately 50% of AFLP patients do not have thrombocytopenia at presentation, unlike HELLP. 4

Clinical Presentation Clues

• Hepatic encephalopathy, if present, is highly suspicious for AFLP over HELLP syndrome. 3
• HELLP syndrome typically presents with right upper quadrant or epigastric pain (65%), nausea/vomiting (35%), and jaundice (40%). 1
• AFLP presents with malaise, headache, nausea, vomiting, right upper quadrant pain, and jaundice, with hypoglycemia being a distinguishing feature. 1, 3

Specific Imaging Algorithm for Your Case

Given the post-LSCS status without PIH:

1. Start with abdominal ultrasound to assess for hepatic abnormalities, subcapsular hematoma, or free fluid. 1

2. Proceed to CT abdomen if:

   • Persistent or worsening epigastric/RUQ pain suggesting hepatic complications 1, 2
   • Ultrasound is technically limited or inconclusive 1
   • Clinical deterioration with falling hemoglobin or platelets suggesting hemorrhage 2
   • Suspicion of hepatic infarction or rupture based on clinical presentation 1, 5

3. MRI without gadolinium is an alternative if CT is contraindicated, though less readily available in emergency settings. 1

Critical Management Points

Monitoring for Hepatic Complications

• Monitor for signs of hepatic hemorrhage or hematoma: abdominal pain, epigastric pain, or right shoulder pain. 6
• Markedly reduced platelet count (<20×10⁹/L) correlates with higher risk of hepatic hemorrhage. 6
• Serial liver function tests and coagulation profiles are essential regardless of imaging decisions. 6

Transfer Considerations

• HELLP complicated by hepatic rupture or acute liver failure should prompt immediate transfer to a transplant center. 1
• Early referral is necessary if signs of hepatic failure develop. 6

Common Pitfalls to Avoid

• Do not delay imaging if clinical suspicion is high for hepatic complications, as HELLP syndrome can progress to life-threatening hepatic infarction or rupture within 48 hours postpartum. 1, 2
• The absence of hypertension does not exclude HELLP syndrome (present in only 85% of cases) or AFLP (often occurs without hypertension). 1, 4
• Symptoms may mimic acute cholecystitis or other gastrointestinal conditions, leading to delayed diagnosis. 1, 7
• Severely ill patients with HELLP syndrome having epigastric pain should undergo CT imaging of the liver. 2