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Gestational diabetes - diabetes that begins during pregnancy

diabetes; gestational; sugar; blood; insulin; glucose; diet;

Gestational diabetes affects up to 5% of pregnant women and usually appears around the middle of the pregnancy. It is usually temporary and goes away after their baby is born.

What causes gestational diabetes?

In pregnancy, the placenta produces hormones that help the baby to grow and develop. These hormones also block the action of the mother’s insulin. This is called insulin resistance.

Because of this insulin resistance, the need for insulin in pregnancy is 2 or 3 times higher than normal. If the body is unable to produce this much insulin, gestational diabetes develops.

When the pregnancy is over and the insulin needs return to normal, the diabetes usually disappears.

As gestational diabetes usually develops around the 24th to 28th week of pregnancy, the baby’s development is not affected. But as glucose crosses the placenta, the baby is exposed to the mother’s high glucose level. This high level of glucose in the baby’s blood stimulates the baby’s pancreas to produce extra insulin. The extra insulin causes the baby to grow bigger and fatter. The result of this may be a large baby that may need to be delivered early when it is not fully mature. When gestational diabetes is well controlled, these risks are greatly reduced. Your baby will not be born with diabetes, but there is an increased risk that your child will develop diabetes later in life (as an adult).

Will I be able to breastfeed my baby?

  • Yes, breastfeeding is still the normal way to feed a baby.

More information

Women's and Children's Hospital (South Australia), Department of Nutrition '

Diabetes Australia 

Pregnancy, birth and baby  Pregnancy, Birth and Baby is a national Australian Government service providing support and information for expecting parents and parents of children, from birth to 5 years of age.

Information in languages other than English

NSW Multicultural Health Communication Service
Diabetes and pregnancy

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The information on this site should not be used as an alternative to professional care. If you have a particular problem, see your doctor or midwife.


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