Prof Jennie Brand-Miller answers your questions.
Are you at risk of gestational diabetes?
All women should be tested for gestational diabetes in every pregnancy. Women with risk factors are more likely to have gestational diabetes but women with no risk factors at all can also have this problem. There are many different risk factors that predict the risk of developing diabetes during pregnancy. One or more of these may be operating in different women.
There are some risk factors that cannot be avoided:
Your genes. If there is a family history of type 2 diabetes, then there is likely to be a genetically-determined tendency to develop the problem. The average age of diagnosis in Australians of Caucasian or northern European origin is about 60 years. Thus a negative family history is not necessarily reassuring as many women in their pregnancy may not yet have a first degree relation who is old enough to have developed or been diagnosed with diabetes.
Your background. In Australia, gestational diabetes is more common in women who come from an ethnic background with a higher overall rate of diabetes or an earlier age of onset. This includes, but is not confined to women from the Pacific Islands, South East Asia, China and the Indian subcontinent.
Your age. With women now delaying their families often until their 30s, they are much further advanced towards the time when they potentially may develop type 2 diabetes in the future. Therefore under the stress of pregnancy this problem can be unmasked.
A previous adverse obstetric history. There is an increased risk of developing gestational diabetes in women who have had previous miscarriages, large babies and adverse pregnancy outcomes.
A previous history of gestational diabetes. Women who have had gestational diabetes in one pregnancy are much more likely to develop this again in subsequent pregnancies. However this is by no means inevitable and there is generally about a 50% recurrence rate. This rate can be reduced by careful attention to diet between the pregnancies, particularly with respect to reducing the intake of saturated fat.
Having PCOS. Women with PCOS have a much higher risk of developing gestational diabetes.
Risk factors that can be reversed or avoided:
Being overweight. Women who are overweight are much more likely to develop gestational diabetes. They are also much more likely to have large babies.
A poor diet, both before and during pregnancy. Women diagnosed with gestational diabetes who follow dietary advice are able to significantly lower their blood glucose levels. Thus it is likely that a less-than-healthy diet during pregnancy may unmask a tendency towards gestational diabetes.
Exercise. Women who exercise regularly are less likely to develop gestational diabetes. Women who are most active before pregnancy have less than half the risk of developing gestational diabetes compared to those who are least active, and those with the highest activity levels in early pregnancy reduce their risk of gestational diabetes by around 25% compared with those who are inactive.
This is an edited extract from my new book (with Dr Kate Marsh and Prof Robert Moses), The Bump to Baby Low GI Eating Plan for Conception, Pregnancy and Beyond (Hachette Australia). In the book we share the latest science to help women enjoy a healthy pregnancy while safeguarding their baby’s future wellbeing. It’s available from bookshops and online in Australia and NZ and as an eBook from Amazon, iTunes etc. We have a website too, where you can visit us, learn more about our book (and look inside), find pregnancy friendly recipes, keep up to date with the latest news about the importance of lifestyle for pregnancy and preconception, download information and weight charts, contact us and link to other useful information. Visit us HERE.
GI testing by an accredited laboratory
Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022