April 5, 2001
Question from New York, USA:
I am 38 weeks pregnant and have gestational diabetes which I am controlling with diet. I occasionally have high readings, but I am pretty much under control. The problem is ketones. They ranged from trace to moderate, a few times a week, not every week. I have read some of the answers to ketones questions on this board, and they said urine ketones are not harmful as long as they are not serum ketones. As a first time mother-to-be, I'm really worried, and have many questions: What is the difference between urine and serum ketones? How do I tell which type I'm having? When I detect ketones in my urine, does that mean I already have ketones in my blood stream and they spill over in the urine? If my body has to burn fat for energy, does that fat energy goes to the fetus as well at the same time? I have read that burning fat for energy doesn't work well with the brain cells. Therefore, burning ketones in the mother is harmful for the fetus' brain development. Is that true? How harmful are ketones to the fetus? I can always tell I'm burning ketones because my baby reacts a lot by moving vigorously. Do you think harm is being done? I know I should be eating and drinking when I notice the sign but sometimes I'm sleeping and couldn't really get up to eat and drink. Do people without diabetes, pregnant or not, burn ketones also?
Ketones are measured in both urine and blood (serum).
The dipstick you use at home on your urine measures ketones in the urine.
Ketones in urine does not always mean ketones in serum.
You are metabolizing fat for your needs not for the baby.
You may use fat for energy, but this does not affect fetal brain development.
Ketones are not a source of calories (energy), but rather a byproduct. Pregnant women frequently have urine ketones and it is not a problem. The same usually goes for gestational diabetes as well. It is rare for someone with gestational diabetes to develop serum ketones. As long as your blood sugar is in good control, this will not happen.