Diabetes is a condition in which your blood sugar (glucose) level is high because there isn't enough of the hormone insulin in your blood, or your body isn't responding to insulin properly. Normally, the body releases insulin after eating to help glucose enter the body cells where it provides nourishment. Insulin helps to keep blood glucose levels to within narrow limits in this way. Diabetes occurs when insulin is either not being produced or the insulin that is being produced is not controlling the levels of glucose in the blood effectively.
During pregnancy, the placenta produces hormones that help your baby grow and develop but they can also affect the action of the insulin. In response, your body has to produce more insulin — you need two or three times more insulin than normal while you are pregnant. If your body isn’t able to produce this much insulin, or if your body becomes resistant to the action of insulin, your blood glucose levels rise to higher than normal levels, leading to gestational diabetes.
Gestational diabetes usually goes away after your baby is born. It may return with subsequent pregnancies though, and having gestational diabetes puts you at greater risk of developing type 2 diabetes, a chronic (long-term) condition.
Gestational diabetes is thought to affect about five percent of women in Australia and you may be at a higher risk of developing gestational diabetes if you:
Gestational diabetes may not have any obvious symptoms. Sometimes you may have symptoms of high blood sugar which can include:
However, these are also common symptoms of a normal pregnancy.
While gestational diabetes may not be an immediate threat to your health, if the condition isn’t managed well, it can increase your risk of other health issues, including:
The higher-than-normal levels of blood glucose circulating in your blood can also affect your unborn baby. Your baby:
There is also a slightly higher chance of stillbirth or death as a newborn, but this is rare as long as blood sugar levels in both you and your baby are well controlled.
Gestational diabetes is usually detected in the 24th to 28th week of pregnancy when you have a routine glucose test, although it can develop and be detected earlier.
For the glucose test, you will be given a glucose-containing drink. After an hour, you will be asked to have a pin prick test that measures the glucose in a tiny amount of your blood. A higher than normal result will be followed by a specific test called an oral glucose tolerance test (OGTT). After an overnight fast, you will be given a drink that contains glucose and your blood will be measured for glucose before the test, one hour after it and then again an hour later. High levels of blood glucose confirm gestational diabetes.
If you are diagnosed with gestational diabetes, your healthcare team will advise you on how to effectively control your blood glucose levels in several ways.
If your diabetes is well controlled and you don't have any other major health problems, a normal birth is possible. But, you may be offered a planned birth either with induced labour or a caesarean section when your pregnancy has reached 38 weeks if your baby hasn’t arrived before this time.
This is because having diabetes means that your baby may be larger than usual and you may have a more difficult labour. Your midwife and doctor will monitor your pregnancy closely and will discuss your options with you.
You and your baby will have your blood sugar levels monitored after the birth to make sure they are back to normal.
You will also be asked to have your blood glucose level tested six to eight weeks after the birth of your baby to make sure that it has gone back to its pre-pregnancy levels. Usually diabetes that develops during your pregnancy goes away within a few weeks of the birth of your baby.
However, if you have had gestational diabetes, you are at greater risk of developing type 2 diabetes in the future. You can reduce the likelihood of this by making healthy lifestyle choices that help reduce this risk. This includes eating a healthy and well-balanced diet, regular physical activity and maintaining the right weight for your height.
For more information about healthy lifestyle choices, please see our Healthy Living hub.
Dietitian’s Association of Australia
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Better Health Channel. Diabetes – gestational. [online] Melbourne, VIC: State Government of Victoria. c1999-2010. [last reviewed Feb 2011, accessed 27 Jun 2011] Available from:
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Last published: 30 July 2011
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