Risk of Gestational diabetes

Gestational diabetes happens in more than three per cent of pregnancies in Ontario. Commonly the condition resolves itself after delivery, but a number of studies have shown that these women are at a very high risk for developing "regular" type 2 diabetes during the later part of life. New research out of the Institute for Clinical Evaluative Sciences (ICES) has observed that even women with mild abnormalities in their blood sugar during pregnancy, previously thought not to have any clinical significance, are 2.5 times more likely to develop type 2 diabetes in comparison to those who had completely normal glucose testing.

• To test for gestational diabetes, women receive a glucose challenge test (GCT) in the late second trimester of pregnancy. If the result of this test is abnormal, they go on to have a diagnostic test, called the oral glucose tolerance test (OGTT). If this test does not show gestational diabetes, women are reassured their glucose levels are normal and that no further testing is needed.
  
• However, recent studies have suggested that women who have even mild abnormalities on either the GCT or the OGTT do actually have subtle differences in their metabolism after pregnancy.
  
• The study examined 15,000 pregnant women aged 20-49 in Ontario who had a mild abnormality on their GCT but did not ultimately get diagnosed with gestational diabetes. They were in comparison to about 60,000 pregnant women who did not have abnormalities on their GCT. The women were followed for 6.4 years after delivery, and those who had had an abnormal GCT were 2.5 times more likely to develop type 2 diabetes in comparison to those who had not had an abnormal GCT.