CMAJ 2000; 162:993-996, abstract reprinted in the ACOG Clinical Review, Volume 5, Issue 6 November/December 2000.

Summary

A very important study has just come out concerning the dilution of the glucose dose given to women during pregnancy and the effect of the dilution on the result of the test.

It is not unusual for pregnant women undergoing glucose tolerance testing to complain that the standard bottle is too sweet and ask if she can take it with some water. This request was and is usually granted, as it has been assumed that the total glucose load, not the volume, was the determining factor. This report mostly contradicts that belief.

While the authors of the study have concluded that the dilution of the glucose drink will probably not affect the results of the two-hour oral glucose tolerance test, intermediate levels will be affected.

As is has been shown that even one abnormal level may be an increased risk for fetal macrosomia (large baby) an abnormal level that is masked by dilution can be critical to the proper diagnosis of gestational diabetes.

If you were told that you were not a gestational diabetic because your glucose levels were within normal limits, and you had the glucose fluid diluted, the test results may not have been correct. This could be very important information.

For women that are pregnant, do not under any circumstance allow the glucose fluid to be diluted by anyone. Be sure to ask and be certain that it has not been diluted by anyone without your knowledge.

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