CA, cholic acid; CDCA, chenodeoxycholic acid; CTG, cardiotocography; CTI, cardiac time interval; DCA, deoxycholic acid; ECG, electrocardiogram; fECG, fetal electrocardiogram; FHR, fetal heart rate; GCA, glycocholic acid; fHRV, fetal heart rate variability; HI, hydrophobicity index; HRV, heart rate variability; ICP, intrahepatic cholestasis of pregnancy; NT-proBNP, N-terminal pro-B-type natriuretic peptide; RMSSD, root mean square of successive differences; SDNN, standard deviation of normal to normal intervals; TCA, taurocholic acid; TSBAs, total serum bile acid; UDCA, ursodeoxycholic acid. This evidence concerns the gene NPPB and intrahepatic cholestasis.