Is exercise safe or useful for gestational diabetic women?

The mainstay of management of the gestational diabetic woman is dietary manipulation to achieve and maintain normoglycemia. If normoglycemia cannot be sustained by diet alone, then insulin therapy is initiated. We instituted a series of studies to observe the value and safety of a cardiovascular fitness program to improve glucose tolerance in gestational diabetic women. We first evaluated the safety for pregnant women of five aerobic exercise machines by observing the effect of these different forms of exercise on uterine activity during the third trimester. We found that upper-extremity exercise produced no uterine contractions, but lower-extremity exercise tended to produce contractions. Upper-extremity exercise, in addition to dietary therapy, was then assigned to 10 gestational diabetic women who were matched for amount of glucose intolerance to 10 gestational diabetic women managed by diet alone. The mean fasting plasma glucose +/- SD after 6 wk was 4.87 +/- 0.34 mM in the diet group versus 3.89 +/- 0.37 mM in the diet-plus-exercise group. The mean postglucose challenge in the diet group was 10.40 +/- 0.16 mM versus 5.9 +/- 1.1 mM in the diet-plus-exercise group. Thus, upper-arm exercise may provide a useful treatment option for gestational diabetes and may obviate the need for insulin.