June 22, 2006
Question from Deal, United Kingdom:
I’m 36 and this is my first pregnancy. During this pregnancy, I moved from one country to another and different standards seem to apply here. Also, due to the move, I missed the gestational diabetes GTT screening at 28 weeks. I’ve had episodes of glucosuria, though (even with a blood glucose of 86 mg/dl [44.8 mmol/L]). How valid is a GTT performed at 33 weeks gestation? I’m in a country that does the 75 gram/two hour test.
Screening for gestational diabetes is typically done between 24 and 28 weeks because it is very unusual for this condition to appear prior to 24 weeks, but it can certainly occur after 28 weeks. Therefore, screening later in pregnancy remains valid. Glucosuria is very common during pregnancy and is not useful as a marker for diabetes, particularly given your normal glucose value. Also, the 75 gram test is valid.