I am 28 weeks pregnant and had a glucose tolerance test a few days ago. My results were:

fasting — 90 mg/dl [5 mmol/L]
one-half-hour — 133 mg/dl [7.4 mmol/L]
one-hour — 168 mg/dl [9.3 mmol/L]
two-hour — 147 mg/dl [8.2 mmol/L]

Are these too high? My doctor has advised me low carbohydrate diet and wants to do a two-hour postprandial test in a month. I am afraid that it may be too long a period to wait for the next result. What is the frequency of tests recommended for gestational diabetes after 28 weeks? How much should I try to maintain the blood sugar levels to? What will be the effect on my baby?

Your fasting blood sugar is normal, but the two-hour value is mildly elevated. This puts you into the category of impaired glucose tolerance, but not overt diabetes. This is why your doctor placed you on the special diet. This may be enough to keep your blood sugar normal.

In my practice, for patients on diet control only, I will check a fasting and one-hour after meal glucose once a week. If your blood glucose is not well controlled, then you may benefit from an oral hypoglycemic agent or even insulin.

When your blood sugars are persistently elevated during a pregnancy, this can result in an excessively large baby. You may want to discuss your plan of management with your obstetrician.

OWJ