Abstract For diagnostic purposes, it is useful to divide liver diseases in pregnant women into three main categories: 1. Liver diseases occurring coincidentally in a pregnant woman (viral hepatitis is the most common cause of jaundice in pregnant patients). 2. Pregnancy occurring in a woman with chronic liver disease. 3. Liver diseases unique to pregnancy, including hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, preeclampsia, HELLP syndrome, and acute fatty liver of pregnancy. These liver diseases, unique to pregnancy, can be considered liver complications of pregnancy itself, and they have a characteristic timing in relation to the trimesters of pregnancy. Hepatitis E and herpes hepatitis, although not related etiologically to pregnancy, characteristically produce a fulminant and often deadly disease in the third trimester of pregnancy. Recent data suggest that most liver disease in pregnancy is pregnancy-related and incidental and chronic liver diseases are uncommon.