Real time reverse transcriptase polymerase chain reaction was applied for the mRNA expression measurement of 8 bile acid transport correlative proteins, organic anion transporting polypeptide (OATP)1A2, OATP1B1, multidrug resistance protein (MRP)1, MRP2, anion exchanger (AE)2, bile salt export pump (BSEP), multidrug resistance 3, and familial intrahepatic cholestasis (FIC)1, in normal human placentas (n=20) and those with ICP (n=20).