
October 14, 2003
Gestational Diabetes
Question from Dallas, Texas, USA:
I am currently 28 weeks pregnant and had the blood glucose test done this past week but I have not received the results yet. I used my husband’s glucose meter to check the other day because I wasn’t feeling well, and I think it was high (159 mg/dl [8.8 mmol/L] one hour after eating). What are normal blood sugar levels should be for someone without gestational diabetes? When is the best time and way to check myself?
Answer:
There is some variation on the criteria for a one hour glucose screening test, but the value I use is less than 135mg/dl [7.5 mmol/L]. If you exceed this value, then it is necessary to do a three-hour test. The criteria are fasting less than 95 mg/dl [5.3 mmol/L], one hour less than 180 mg/dl [10 mmol/L], two-hour less than 155 mg/dl [8.6 mmol/L], three-hour less than 140 mg/dl [7.8 mmol/L]. Morning fasting glucose should be 70-90 mg/dl [3.9-5 mmol/L], and one hour after a meal it should less than 130 mg/dl [7.2 mmol/L] or less than 120 mg/dl [6.7 mmol/L] at two hours. Thus, your value of 159 mg/dl [8.8 mmol/L] is certainly concerning. However, it takes formal testing to make a diagnosis of gestational diabetes. The usual times for testing are upon waking in the morning and just before and either one or two hours after meals.
OWJ