A double-blind, randomised, cross-over study comparing the 50g OGTT and the 75g OGTT for pregnant women in the third trimester

Abstract

There is little consensus in the conduct and interpretation of the oral glucose tolerance test (OGTT) in pregnancy. In Singapore much data has been accumulated about the 50g OGTT while the converse is true of the 75g OGTT. A double-blind, randomised, crossover study of 56 subjects in the third trimester was conducted to compare both glucose challenges to determine if there was a difference in glucose handling in the context of a two hour OGTT. A significant difference (p < 0.001, t = 5.76) was found at two hours where the mean glucose concentrations were 5.2 +/- 0.8 mmol/L and 6.2 +/- 1.4 mmol/L for the 50g and 75g OGTT respectively. These findings suggest that the 75g OGTT is potentially more effective in unmasking pregnant subjects with impaired glucose tolerance.