S5672 A Case of Presumed Acute Fatty Liver of Pregnancy in the Second Trimester Progressing to Fulminant Liver Failure Requiring Liver Transplantation

Introduction: Acute fatty liver of pregnancy (AFLP) is a rare, life-threatening obstetric emergency that typically occurs in the third trimester and requires urgent delivery of the fetus. While delivery usually corrects acute liver failure (ALF), rare cases progress to fulminant liver failure necessitating liver transplantation. We present a case of presumed second-trimester AFLP with atypical pathology and fulminant liver failure that ultimately required transplantation. Case Description/Methods: A 31-year-old primigravida at 20 weeks and 4 days gestation presented with 1 week of nausea and vomiting. She was found to have severe transaminitis (aspartate aminotransferase 2737 U/L, alanine aminotransferase 4,669 U/L), total bilirubin 7.11 mg/dL, international normalized ratio >10, and hyperammonemia of 188 µmol/L. She then became encephalopathic and developed asterixis with computed tomography head concerning for cerebral edema, prompting emergent continuous renal replacement therapy (CRRT) and administration of hypertonic saline and mannitol. No liver biopsy was attempted given the high bleeding risk. Negative infectious workup and fulfillment of greater than 6 Swansea Criteria supported presumed AFLP diagnosis. Therefore, she underwent induction of labor with spontaneous delivery of the fetus and subsequent dilation and curettage. Despite CRRT and administration of prothrombin complex concentrate and fresh frozen plasma, encephalopathy and coagulopathy persisted. As she had no liver recovery, she underwent rapid liver transplant evaluation and Status 1A listing, with successful liver transplantation the following day. Explant pathology revealed severe lobular hepatitis with focal necrosis. Discussion: This case, with the extreme transaminitis and coagulopathy, is more severe than past reported second-trimester AFLP cases requiring transplantation (transaminases <1,000 U/L, international normalized ratio <3). Additionally, the pathology lacked the hallmark microvesicular steatosis traditionally seen in AFLP and instead had lymphocytic predominance and areas of necrosis. This suggests possible advanced necrosis and inflammatory infiltrate obscuring microvesicular steatosis. Perhaps liver biopsy earlier in her clinical course would have demonstrated the hallmark findings but given her rapid clinical decline, pathology was only obtained at the time of transplant. Despite immediate delivery of the fetus, the patient still needed liver transplantation, underscoring the need for prompt recognition of AFLP, even in early gestation, and for expeditious transplant work-up in the setting of ALF in patients with presumed AFLP.