INTRODUCTION
Gestational diabetes mellitus (GDM) is defined as any degree of glucose
intolerance with onset or first recognition during pregnancy1. Prevalence ranges from 1 to 14% of all
pregnancies, depending on the population and the diagnostic tests and
criteria 1, 2. In Geneva, Switzerland, 11% of
pregnant women are currently diagnosed with GDM according to the IADPSG
criteria 3. Initial management of GDM consists of diet
and monitoring glucose levels. When euglycemia is not achieved by diet
alone, insulin therapy is prescribed 2.
There is good evidence that exercise improves insulin sensitivity in
non-diabetic patients 4. The benefit of exercise is
best seen in milder forms of type 2 diabetes 5, which
is usually the case with GDM. A systematic review of observational
studies showed that women exercising before pregnancy or in early
gestation have a lower risk of GDM 6. Results of
randomised trials evaluating the effects of programs in early pregnancy
have shown that exercise can prevent GDM 7.
In women who develop GDM, increasing the daily time spent in moderate
physical activity may be a useful therapeutic approach to improve the
control of glycaemia and decrease the need for prescription of insulin.
Women see the need for insulin as a failure of their initial efforts to
control GDM. Injections, careful glucose monitoring and adjustment of
the doses are perceived as an additional burden. Increased physical
activity in pregnant women with GDM could improve the general health,
decrease the risk of caesarean section, and of mother and child
morbidity associated with GDM 8.
The effects of exercise programs for women diagnosed with GDM were
evaluated in 11 trials including 638 women. The systematic review of
these trials showed that exercise programs reduce fasting and
post-prandial glycaemia, but there were no apparent benefits on
clinically significant outcomes 9. One study proposing
three exercise sessions per week (one supervised, two at home) suggested
a reduction in insulin prescription 10. Other trials
tested more intensive exercise interventions, and showed a benefit on
glycaemia control 10. For many women consulting in our
clinic such intensive schedules are unfeasible because of travel and
time constraints. Given that in our setting women generally consult on a
weekly basis, we designed a voluntary, lightweight, easily implemented
and low-cost once-weekly exercise program. Our objective was to evaluate
the effect of this program on insulin prescription in women with GDM.