Most people are well aware of two of the main forms of diabetes – type 1, which usually first appears in young people; and the more common type 2, which often emerges in the over 40s and is associated with obesity and sedentary lifestyles. We hear far less about the third form, gestational diabetes, which temporarily affects as many as 16% of pregnant women.
Gestational diabetes is defined as glucose intolerance that is first diagnosed during pregnancy. Women with gestational diabetes are unable to produce enough insulin to meet the extra demands of carrying a child, the risk of which increases with each successive pregnancy. For the majority of them, the condition is diagnosed during the second or third trimester. Many of the risk factors, such as age, obesity and family history, are the same as those for type 2 diabetes. And, just like type 2 diabetes, many countries have seen prevalence rates rise over the past few decades.
Most women with gestational diabetes return to normal glucose tolerance after delivery, but there are immediate risks for both mother and baby. These include spontaneous pre-term labour, delivering a large baby, infant respiratory distress syndrome and heart muscle diseases.
But gestational diabetes is also associated with an increased risk of developing type 2 diabetes in later life: seven times that of the general population. This equates to a staggering 50% chance of developing type 2 diabetes within ten years. The children of women who have had gestational diabetes are also six times more at risk of developing type 2 diabetes as the general population.
Women with gestational diabetes are not unaware of these risks. Claire Eades, a University of Stirling researcher, recently interviewed some Scottish women who had had the condition. At the time of diagnosis, most had worried about the possible side effects to the baby, and talked graphically about their fears of delivering a big baby. Some changed their lifestyles during pregnancy as a result.
The women usually also knew their increased risk of type 2 diabetes, having been told by their healthcare professionals. But once they had delivered a healthy baby and returned to normal glucose tolerance, many quickly forgot. One compared gestational diabetes to maternity clothes – put away and forgotten until the next pregnancy.
The case for action
Since the risks of type 2 diabetes can be reduced by taking more exercise, a healthy diet and maintaining a healthy weight, we need to find ways to encourage this where it is needed. The later stages of pregnancy and early stages of motherhood are hardly the best time when women are dealing with big life changes and pressing demands on time and energy.
To date, there have been few attempts to measure which kinds of interventions are best to encourage women to take the best steps – which possibly reflects the scale of the challenge. There is some evidence that women are more likely to respond positively if the interventions include face-to-face interaction either with peers or professionals, if their partners are involved, and if the women are offered childcare support. We’ve been asking women who have had gestational diabetes about what they think would be the best kinds of interventions to try out.
We probably also need to remind women of the increased risk of type 2 diabetes more regularly once the early-motherhood period has passed. It is therefore time to think about raising the profile of gestational diabetes across the whole population. It offers a big opportunity to gain ground in the fight against diabetes. World diabetes rates are set to rise 50% to nearly 600m by 2035 – and the disease has been described as a global pandemic. So long as gestational diabetes is out of sight and out of mind except during pregnancy, we won’t be able to use it to make people aware of the importance of a healthy lifestyle and to prevent more cases of type 2. Instead, it offers a big opportunity to gain ground in the fight against diabetes.
Josie receives funding from the Medical Research Council and the Chief Scientist Office