**4.1 Liver pathology as a cause of preeclampsia**

Preeclampsia is associated with three unique liver lesions described as liver lesions of preeclampsia, HELLP syndrome, and acute fatty liver of pregnancy. HELLP syndrome has classical periportal or focal parenchymal liver necrosis. There is thrombotic microangiopathy with resulting hemolysis and liver damage. Few cases of HELLP are associated with defects in beta-oxidation of fatty acids. There is microangiopathic hemolytic anemia with schistocytes, thrombocytopenia, and elevated levels of ALT/AST/LDH/bilirubin. HELLP may even develop postpartum, so the placenta is an unlikely cause of HELLP syndrome (**Figure 6**).

Acute fatty liver of pregnancy is due to defective oxidation of beta fatty acids. There is mitochondrial deficiency of long-chain 3-hydroxyacyl coenzyme A dehydrogenase in fetus. This leads to accumulation of 3-hydroxyacyl metabolites that are toxic to the liver. Half of the pregnancies with acute fatty liver of pregnancy develop preeclampsia (**Figure 7**).
