Where a glucose challenge test (GCT) is performed, plasma glucose is measured one hour after either a 50g
or 75g oral glucose load has been administered in a non-fasting state. RANZCOG (2011) explain
that plasma levels greater than or equal to 7.8mmol/l after the 50g oral load, and greater than or
equal to 8.0 mmol/l after the 75g load, are regarded as positive and the woman should undergo a
full glucose tolerance test (GTT).