Acute Fatty Liver of Pregnancy
Acute fatty liver of pregnancy is a cause of acute liver failure that can develop in the late second or third trimester. It occurs in approximately 1 in 16,000-20,000 pregnancies.[43] Maternal mortality is up to 20%, with fetal mortality of up to 23%.[44] Acute fatty liver is more common in first pregnancies and with twin pregnancy, and it appears to be related to impaired mitochondrial beta-oxidation of long-chain fatty acids[45,46] and fetal deficiency of long-chain 3-hydroxyl-CoA dehydrogenase (LCHAD). Mothers who are heterozygous for LCHAD deficiency and who are carrying homozygous LCHAD-deficient fetuses are at risk. The potentially toxic products of impaired fatty acid metabolism arise from the fetus or the placenta and accumulate within the mother. These same changes have been observed in some patients with HELLP syndrome.
Initial symptoms include malaise (100%), nausea, vomiting, and flu-like illness (75%).[47] Other possible symptoms include epigastric or right upper quadrant abdominal pain (43%), headache (40%), jaundice, fever, pruritus, and weight gain.[47] Transient diabetes insipidus,[48] hypertension, and/or peripheral edema may be present because concurrent preeclampsia is frequent. Patients can progress to overt hepatic failure with jaundice, hepatic encephalopathy, ascites, hypoglycemia, lactic acidosis, adult respiratory distress syndrome, hyperuricemia, acute tubular necrosis, and pancreatitis. Although symptoms and signs are similar to those of preeclampsia and HELLP syndrome, aminotransferase levels tend to be much higher and hypoglycemia more severe in acute fatty liver of pregnancy.
Patients suspected of having acute fatty liver of pregnancy should have an immediate evaluation, including a complete blood count, platelet count, blood urea nitrogen level, creatinine level, INR, and liver tests. Findings can include leukocytosis, thrombocytopenia, proteinuria, aminotransferase and bilirubin elevation (typically < 5 mg/dL), azotemia, increased INR, and occasionally signs of DIC or lactic acidosis. Hypoglycemia is a poor prognostic sign, as it would be in any patient with acute hepatic failure. For patients who recover, clinical evidence of cholestasis can persist for weeks. A liver biopsy is rarely needed for diagnosis, but if obtained, histology shows microvesicular fatty changes of pericentral hepatocytes, ballooning hepatocyte changes, canalicular cholestasis, and focal hepatic necrosis.
Treatment should include supportive care with monitoring of blood glucose levels, administration of fluids, and management of complications. Prompt delivery of the fetus should be considered. Coagulopathy may persist for several days following delivery. Patients should be monitored for signs of infection, and prophylactic antibiotics are often recommended. Liver transplantation has been performed in some patients.[49] Acute fatty liver of pregnancy recurs in 20% of patients during subsequent pregnancies.[50]
Clinical Implications
Liver disease that becomes apparent during pregnancy can be a consequence of pregnancy, related to disorders developing during pregnancy (such as viral hepatitis), or a preexisting hepatic disorder that becomes apparent during pregnancy. Most liver disorders that are a consequence of pregnancy (except hyperemesis gravidarum) develop during the third trimester. Patients with symptoms or signs of liver disease should be carefully evaluated with a thoughtful history and physical examination and laboratory studies, including liver tests, platelet count, and coagulation studies. If radiologic imaging is needed, hepatic ultrasonography is a safe modality at all stages of pregnancy. If an MRI is considered, it should be completed without contrast. Other hepatic disorders must also be considered as causes for hepatic disease developing during pregnancy.
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Cite this: Liver Disease in Pregnancy - Medscape - Apr 08, 2013.
