Total bile acids in serum blood samples from 325 subjects were estimated. Study group consisted of 50 nonpregnant women, 40-in the I trimester, 50-in the II and 100-in the III trimester of gestation, 55 patients in the third day of puerperium and 30 newborn infants (cord serum). All women were healthy, their age varied between 20 and 36 years. Children were mature, born in good condition (Apgar score > 8 points). Bile acids concentration were determined using enzymatic method with reagent kits by Nycomed Pharme, Norway. In the course of pregnancy continuous increase of investigated compounds was observed. The concentration of bile acids in puerperium was lower than in the III trimester of pregnancy and equal to that determined in cord serum. Authors conclude that during normal, uneventful course of gestation symptomless, benign intrahepatic cholestasis occurs.