Diagnosis
The diagnosis of acute fatty liver of pregnancy is usually made on clinical grounds by the treating physician, but differentiation from other conditions affecting the liver may be difficult. The diagnosis of acute fatty liver of pregnancy is suggested by jaundice with a lesser elevation of liver enzymes, elevated white blood cell count, disseminated intravascular coagulation, and a clinically unwell patient.A liver biopsy can provide a definitive diagnosis, but is not always done, due to the increased chance of bleeding in acute fatty liver of pregnancy. Often testing will be done to exclude more common conditions that present in a similar fashion, including viral hepatitis, pre-eclampsia, HELLP syndrome, intrahepatic cholestasis of pregnancy, and autoimmune hepatitis. Pathology
If a liver biopsy is needed for diagnosis of the condition, the mother should be appropriately stabilized and treated to reduce bleeding related complications. The diagnosis can be made by a frozen-section (as opposed to a specimen in formalin) that is stained with the Oil red O stain, that shows microvesicular steatosis (or small collections of fat within the liver cells). The microvesicular steatosis usually spares zone one of the liver, which is the area closest to the hepatic artery. On the regular trichrome stain, the liver cell cytoplasm shows a foamy appearance due to the prominence of fat. Necrosis is rarely seen. The diagnosis can be enhanced by electron microscopy which can be used to confirm the presence of microvesicular steatosis, and specifically the presence of megamitochondria and paracrystalline inclusions.
Liver diseases with similar appearances include Reyes syndrome, drug-induced hepatitis from agents with mitochondrial toxicity, including nucleoside reverse transcriptase inhibitors used to treat HIV, and a rare condition known as Jamaican vomiting sickness which is caused by the eating of the unripened Ackee fruit. Treatment
Acute fatty liver of pregnancy is best treated in a centre with expertise in hepatology, high-risk obstetrics, maternal-fetal medicine and neonatology. The physicians who treat this condition will often consult with experts in liver transplantation in severe cases. Admission to the intensive care unit is recommended.Initial treatment involves supportive management with intravenous fluids, intravenous glucose and blood products, including fresh frozen plasma and cryoprecipitate to correct DIC. The foetus should be monitored with cardiotocography. After the mother is stabilized, arrangements are usually made for delivery. This may occur vaginally, but, in cases of severe bleeding or compromise of the mothers status, a caesarian section may be needed. Often AFLP is not diagnosed until the mother and baby are in trouble, so it is most likely that an emergency C-section is needed.The complications of acute fatty liver of pregnancy may require treatment after delivery, especially if pancreatitis occurs. Liver transplantation is rarely required for treatment of the condition, but may be needed for mothers with severe DIC, those with rupture of the liver, or those with severe encephalopathy. Epidemiology
Acute fatty liver of pregnancy is a rare condition and occurs in approximately one in 7,000 to one in 15,000 pregnancies.