Abnormal liver tests occur in 3%-5% of pregnancies, with many potential causes, including coincidental
liver disease (most commonly viral
hepatitis or
gallstones) and underlying chronic
liver disease. However, most
liver dysfunction in pregnancy is pregnancy-related and caused by 1 of the 5
liver diseases unique to the pregnant state: these fall into 2 main categories depending on their association with or without
preeclampsia. The
preeclampsia-associated
liver diseases are
preeclampsia itself, the
hemolysis (H), elevated liver tests (EL), and low platelet count (LP) (
HELLP) syndrome, and
acute fatty liver of pregnancy.
Hyperemesis gravidarum and
intrahepatic cholestasis of pregnancy have no relationship to
preeclampsia. Although still enigmatic, there have been recent interesting advances in understanding of these unique pregnancy-related
liver diseases.
Hyperemesis gravidarum is intractable, dehydrating
vomiting in the first trimester of pregnancy; 50% of patients with this condition have
liver dysfunction.
Intrahepatic cholestasis of pregnancy is
pruritus and elevated
bile acids in the second half of pregnancy, accompanied by high levels of
aminotransferases and mild
jaundice. Maternal management is symptomatic with
ursodeoxycholic acid; for the fetus, however, this is a high-risk pregnancy requiring close fetal monitoring and early delivery. Severe
preeclampsia itself is the commonest cause of hepatic tenderness and
liver dysfunction in pregnancy, and 2%-12% of cases are further complicated by
hemolysis (H), elevated liver tests (EL), and low platelet count (LP)-the
HELLP syndrome. Immediate delivery is the only definitive
therapy, but many maternal complications can occur, including
abruptio placentae,
renal failure, subcapsular
hematomas, and hepatic
rupture.
Acute fatty liver of pregnancy is a sudden
catastrophic illness occurring almost exclusively in the third trimester; microvesicular fatty infiltration of hepatocytes causes
acute liver failure with coagulopathy and
encephalopathy. Early diagnosis and immediate delivery are essential for maternal and fetal survival.