I am 35 weeks pregnant and just now had a screening testing for gestational diabetes. I had a two hour post-prandial value of 151 mg/dl [8.4 mmol/L]. Is glucose screening still going to give me a valid result at this late date in the pregnancy? Don’t glucose levels rise linearly throughout pregnancy, which is why they recommend it be done at 24 to 28 weeks? If I ate 10 grams extra sugar (above the 100 grams I was supposed to), would that be enough to throw off the results?

The reason the glucose screening test is done at 24 to 28 weeks is that gestational diabetes rarely occurs prior to this time. In a normal pregnancy, blood glucose does not increase. In some women, gestational diabetes may not appear until late in the pregnancy. It is unclear from your question why the glucose value was obtained. A glucose of 151 mg/dl p8.4 mmol/L] two hours after a meal is elevated. If that were the value at the two hour mark during the three hour 100 gram glucose test, then it is acceptable. Understand that the 100 gram glucose test is loading you with a large amount of glucose to see how you respond. I would suggest reviewing the results of your glucose testing with your doctor. It may be that all you need to do is some dietary adjustment. Possibly your doctor may start you on glyburide (an oral hypoglycemic agent).

OWJ