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 micromol/l vs. 0.7+/-0.2 micromol/l, p<0.01) and cholic acid was a major species (19.0+/-13.1 micromol/l), reflecting the elevated concentrations in maternal serum (48.9+/-21.0 micromol/l, total bile acids; 33.9+/-16.7 micromol/l, cholic acid. Following ursodeoxycholic acid administration, total bile acids and cholic acid levels in colostrum diminished to 5.7+/-2.5 micromol/l and 3.6+/-1.5 micromol/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.