Elevated levels of bile acids in colostrum of patients with cholestasis of pregnancy are decreased following ursodeoxycholic acid therapy

Background/Aims: Intrahepatic cholestasis of pregnancy is characterised by increased levels of serum bile acids. Ursodeoxycholic acid therapy corrects the serum bile acid profile. The aims of this study were: (i) to investigate bile acid excretion into colostrum of women with intrahepatic cholestasis of pregnancy; (ii) to compare concentrations of bile acids in serum and colostrum of non-treated and ursodeoxycholic acid-treated patients; and (iii) to clarify whether ursodeoxycholic acid is eliminated into colostrum following treatment. Methods: Bile acids were assessed by gas chromatography and high-performance liquid chromatography in serum collected at delivery, and in colostrum obtained at 2±1 days after labour, from patients with intrahepatic cholestasis of pregnancy, non-treated (n=9) and treated (n=7) with ursodeoxycholic acid (14 mg/kg bw per day, for 14±7 days) until parturition. Results: The concentration of total bile acids in colostrum from patients with intrahepatic cholestasis of pregnancy was higher than in normals (23.3±14.8 μmol/1 vs. 0.7±0.2 μmol/l, p<0.01) and cholic acid was a major species (19.0±13.1 μmol/l), reflecting the elevated concentrations in maternal serum (48.9±21.0 μmol/l, total bile acids; 33.9±16.7 μmol/l, cholic acid. Following ursodeoxycholic acid administration, total bile acids and cholic acid levels in colostrum diminished to 5.7±2.5 μmol/l and 3.6±1.5 μmol/l, respectively; the proportion of cholic acid decreased (60.6±8.0% vs. 76.8±5.0%, p<0.05). The ursodeoxycholic acid concentration in colostrum was maintained following treatment; its increased percentage (9.4±3.2% vs. 1.0±0.2%, p<0.01) was still lower than in maternal serum (20.8±3.6%, p<0.05). Only a small proportion (<1%) of lithocholic acid was found in colostrum following therapy. Conclusions: Bile acid concentrations are elevated and cholic acid is the major species accumulating in colostrum, reflecting serum bile acid profiles in intrahepatic cholestasis of pregnancy. Ursodeoxycholic acid therapy decreases endogenous bile acid levels in colostrum.