
Abstract
Objective The total bile acid (TBA) concentration criterion for diagnosing intrahepatic cholestasis of pregnancy varies in the published literature. The purpose of this study was to establish pregnancy-specific reference ranges for the TBA concentration among Latina women.
Study Design Self-identified Latina women (n = 211) over 18 years of age with a singleton pregnancy were recruited and had random serum samples drawn during the second and third trimesters. The total and fractionated bile acid concentrations were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and reference ranges were calculated. Laboratory-provided general reference ranges from a general population of adult men and nonpregnant women were used for comparison.
Results The TBA reference range for our Latina pregnant population (<8.5 µmol/L) was markedly lower than the laboratory-provided reference range (4.5 to 19.2 µmol/L).
Conclusion These data suggest that the upper TBA concentration reference range in our Latina pregnant population is 8.5 µmol/L, based on LC-MS/MS measurements.
Keywords
cholestasis - pregnancy - bile - acid - range