Conclusions
In our study we demonstrated that a normal pregnancy is a
sub-cholestatic state and is associated with physiological elevation of
TSBA levels compared to non-pregnant adults. By defining
pregnancy-specific reference ranges, we can avoid unnecessary diagnosis
of ICP that is strongly correlated with maternal anxiety and active
management.
We recommend that higher threshold should be used for the diagnosis of
ICP. We suggest using the upper limit in the normal pregnant population:
fasting TSBA values ≥14 µmol/L and postprandial TSBA values ≥20 µmol/L.
We also suggest both values should be measured, as each provide
different information: the fasting measurement is more specific for the
diagnosis and the postprandial is essential for risk stratification and
severity assessment. Since TSBA values usually increase after food
intake, the measurement should not be random, as two different
thresholds should be used for the fasting and postprandial measurements.