Total bile acids testing: fifth-generation method in cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) or obstetric cholestasis is a pregnancy-specific liver disorder. Characterised by maternal pruritus in the absence of a rash and increased total bile acids (TBA) levels, ICP is a severe, yet reversible, cholestasis commonly occurring in the second and third trimester of pregnancy. Diagnostic and therapeutic guidelines for ICP are lacking, which is of concern as ICP can have significant fetal risks.^1,2

Intrahepatic cholestasis of pregnancy restricts the flow of bile through the gall bladder causing bile acids to build up in the liver,² resulting in bile acids leaking into the bloodstream where they are detected at levels that cause concern.  It has been documented that TBA levels in ICP can reach as high as 100 times the upper limit of levels seen in a normal pregnancy. Moreover, a doubling in maternal serum TBA levels results in a 200% increase in the risk of stillbirth. Additionally, elevated serum bile acids can affect the fetal cardiovascular system causing issues such as cardiac rhythm disturbances.³

As with most disorders and diseases, several risk factors are associated with TBA in ICP, including family history, use of oral contraceptives, assisted reproduction techniques, and multiple gestation. Genetic influence accounts for approximately 15% of ICP cases. Dietary selenium is a contributing environmental factor as serum levels often decrease throughout pregnancy. Furthermore, incidences of ICP rise in the winter months, coinciding with the fact that selenium levels are naturally lower during these months.^2,3