Results
Reference intervals of 4.4-14.1 µmol/L for fasting TSBA, and 4.7-20.2 µmol/L for postprandial TSBA were established. The postprandial values were significantly higher than the fasting measurements, with a mean increase of 1.77 µmol/L (22%). A correlation between fasting TSBA levels and postprandial levels was found, as well as with fetal gender, parity, and the use of assisted reproductive technologies. A seasonal pattern was noticed for both fasting and postprandial TSBA, with the highest values in the winter season (p < 0.01 and 0.02, respectively).