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MS WordPerinatologist Corner - C.E.U/C.M.E. Modules
Diabetes In Pregnancy Series
Sponsored by The Indian Health Service Clinical Support Center
PART 2: Management, delivery, and postpartum
2. Diet and exercise
Case continued
The rest of her intake can be divided between protein and fats, but hopefully, for her long-term cardiovascular health, you will not teach her to eat too much fat, and the fat that she does eat will be of the “heart healthy” polyunsaturated variety. Many traditional American Indian / Alaska Native (AI/AN) diets are low in carbohydrates, and you may be able to appeal to the patient’s cultural tradition to foster a healthy diet for her.
Diet
Breakfast should be the patient’s smallest meal if possible because the “diabetogenic” hormones of pregnancy tend to be secreted in a diurnal fashion, with peaks in the mornings. Many AI/AN women eat at irregular intervals, when they are hungry, and do not eat the standard Anglo “three square meals” a day. You therefore may have to adjust your therapy around that, or see if it is feasible for her to make some further changes in her life-style as regards when she will eat, as well as what she will eat.
It would be hoped that she would not gain more than 20 pounds during the pregnancy because of her already high BMI. While pregnancy is not the time for weight loss, the more adipose tissue the patient has, the more insulin resistant she will be. Many heavy-set women will have almost no weight gain during pregnancy and still have a normally grown or even macrosomic infant. This again points out our lack of evidence-based interventions for this disorder.
Medical nutrition therapy (MNT), while intuitively reasonable, has never been demonstrated in a randomized control fashion to have a significant impact on perinatal outcomes, although it will help short-term glucose control. The Cochrane Library says “There is not enough evidence to evaluate the use of primary dietary therapy for women who show impaired glucose metabolism during pregnancy.”
Exercise
If diet is not proven to work in the literature, then what is an evidence-based helpful intervention? Exercise has randomized data to support its benefit in control of fasting and postprandial glucose. (Bung et al, Jovanovic-Peterson et al) Dyck et al describe a successful exercise program in Aboriginal women in Saskatoon, Saskatchewan.
An “exercise prescription” is something from which women with GDM should benefit. Something as simple as walking at a comfortable pace for 20-30 minutes after meals will usually favorably impact post-prandial glucose values and result in lower birth weight if done as part of a regular regimen.
A high-fiber diet has also been proposed as helpful for glycemic control because of its effect on intestinal transit time and decreased nutrient absorption, but this has not been able to be confirmed in the trials.
McFarland et al reported that women with GDM should be prescribed diet therapy alone for two weeks before they are prescribed insulin. In those with fasting glucose above 95 mg/dL insulin may be prescribed after 1 week of therapy or at diagnosis.
For more information on this and other issues in this module, also see the ANMC Diabetes in Pregnancy Guidelines.
