Serum fructosamine was measured in 569 samples of pregnant women without gestational diabetes. We defined abnormal fructosamine as mean + 2SD, and analysed its potential value to detect patients with gestational diabetes diagnosed with current screening criteria. We found serum fructosamine to be an insensitive parameter: Measured at the time of a positive 50 g glucose screening, SF would have detected 4/48 gestational diabetes.