RESUMO
The clinical features, laboratory investigations and histopathology of 12 patients with idiopathic acute fatty liver of pregnancy are presented. Repeated vomiting, starting in the last trimester, was the cardinal symptom. Seven patients had proteinuria, hypertension and peripheral oedema before jaundice appeared. Caesarian section and induction of labour led to a lower than expected maternal mortality (33 X 3 per cent) and foetal mortality (66 X 7 per cent). There was a high incidence of twin and male births. Neutrophilia, thrombocytopenia and normoblasts were a uniform feature and uric acid levels were universally high. These findings may be useful in diagnosis in conjunction with liver function tests. Hepatic histology showed pathognomonic microvesicular fat in swollen hepatocytes with central nuclei and centrilobular distribution. However, a diffuse pattern and the presence of significant inflammation and fibrin deposits led to an initial misdiagnosis in two patients. Histology of fetal livers and five placentae was normal. Seven subsequent normal pregnancies occurred in four patients. Acute fatty liver of pregnancy may be confused with acute hepatitis or toxaemia on both clinical and histological grounds. Accurate diagnosis should lead to improved management and lessen maternal and fetal mortality. This justifies more intensive and urgent investigation of nausea, vomiting and jaundice in the last trimester of pregnancy.