Smith DD, Kiefer MK, Lee AJ, et al. - Researchers examined whether fasting and nonfasting bile acid levels differ between asymptomatic and symptomatic pregnant women. Findings from two prospective cohort studies delineating bile acid levels in the fasting and nonfasting state in pregnancy are reported in this study. Measurement of bile acid levels was done during the second and third trimesters after fasting and again 2 hours after a standardized meal. Symptomatic women with singleton pregnancies formed the second cohort in whom measurement of fasting and nonfasting bile acid levels was done at the time of symptom evaluation. The asymptomatic cohort comprised a total of 27 women. Findings revealed significantly lower fasting bile acid levels when compared with nonfasting values in both asymptomatic and symptomatic pregnant women. Nonfasting bile acid levels in asymptomatic women were often more than 10 micromoles/L whereas fasting values were not. In symptomatic women, 23% fewer diagnoses of cholestasis were observed because of fasting bile acid levels vs nonfasting values. Based on these findings, they emphasize considering fasting evaluation of bile acid levels or a higher threshold for diagnosis of cholestasis.