
January 19, 2003
Gestational Diabetes
Question from Madison, Wisconsin, USA:
At 28 weeks into my pregnancy, I failed the one-hour glucose challenge by three points (143 mg/dl [7.9 mmol/L]). but these results got misplaced and weren’t discovered until my next appointment at 32 weeks. At that time, they then had me do a three-hour glucose test. My fasting was 88 mg/dl [4.9 mmol/L], my one-hour was 192 mg/dl [10.7 mmol/L], my 2 hour was 185 mg/dl [10.3 mmol/L], and my three-hour was 120 mg/dl [6.7 mmol/L]. Since my one-hour was just slightly over (by two points) and my two- hour was way over, technically I “failed”, but my three-hour dropped nicely.
I don’t mind following the diet or checking my blood sugar, but I hate to be classified with gestational diabetes because the medical interventions surrounding my pregnancy and birth go way up. Can I argue with the results of my three-hour glucose test and request a retest? I’m only two points over. What is the accuracy of the glucose test? If it’s plus or minus five points, that could be considered passing. Is there anything I should do prior to taking the test that would make the test more accurate (i.e., carb load for three days prior, eating no sugar for three days prior? My care-provider gave me no instructions on that.
Answer:
The most recent diagnostic criteria for gestational diabetes. using the three hour test are: fasting: greater than 95 mg/dl [5.3 mmol/L]; one-hour: greater than 180 mg/dl [10 mmol/L], two-hour greater than 155 mg/dl [8.6 mmol/L] and 3 hour greater than 140 mg/dl [7.8 mmol/L]. So, you had two fairly significantly abnormal values.
As long as only diet is needed to control your blood sugar, then your pregnancy can be managed the same as a woman without diabetes, and it is not worth the trouble of repeating the test.
OWJ