Understanding gestational diabetes

Understanding gestational diabetes

Diabetes is a serious complex condition which can affect the entire body.

Diabetes requires daily self-care and if not managed well can lead to other diabetes related health conditions.

While there is currently no cure for diabetes, you can live an enjoyable life by learning about the condition and effectively managing it.

It is really important to have regular check-ups with your health care team which can include your doctor, diabetes nurse, practice nurse, pharmacist, podiatrist, optometrist, dietitian etc.

As diabetes can be a 'silent' condition sometimes people have the condition without realising.

It is always good to have a chat with your regular doctor if you have any concerns.

You don't have to wait till you have diabetes to start looking after your health, you can start today by making small changes.

There are different types of diabetes; all types are complex and serious.

There is no 'good' or 'bad' diabetes, it isn't 'a little touch of sugar' or the 'mild' form of diabetes. Diabetes is diabetes and should be taken seriously.

The three main types of diabetes are type 1, type 2 and gestational diabetes.


Gestational diabetes is a form of diabetes that occurs during pregnancy.

About 15 per cent of pregnant women will develop gestational diabetes, usually around the 24th to 28th week of pregnancy.

In most cases, blood glucose levels return to target ranges after the baby is born and the woman no longer has diabetes.

However, some women will continue to have high blood glucose levels after delivery, leading to a diagnosis of type 2 diabetes.

During pregnancy, some of the hormones produced by the placenta reduce the action of insulin.

The pancreas then needs to produce extra insulin to keep blood glucose levels in the target range.

If the pancreas is unable to produce enough insulin, blood glucose levels rise and gestational diabetes develops.

Managing gestational diabetes can help keep blood glucose levels in the target range for a healthy pregnancy.

If blood glucose levels are high during pregnancy, glucose passes across the placenta to the baby, who then makes extra insulin.

This can make the baby grow too big, which can cause problems during labour, and increase the risk of early delivery or the need for a Caesarean section.

After the birth, the baby may have a greater risk of low blood glucose levels (hypoglycaemia or hypo).

This is because the baby is no longer receiving extra glucose from their mother, but they continue to make extra insulin, causing their blood glucose levels to drop.

Women with gestational diabetes also have an increased risk of developing high blood pressure during pregnancy.

All pregnant women should be screened for gestational diabetes at 24 to 28 weeks (except those women who have had type 1 or type 2 diabetes diagnosed before pregnancy).


Women who have risk factors for gestational diabetes may be screened earlier in their pregnancy.

Gestational diabetes is diagnosed using an oral glucose tolerance test (OGTT). This is done at a pathology lab.

You will need to fast overnight before having this test.

Blood will be taken to check your fasting blood glucose level.

After this, you will be given a sugary drink and have your blood tested one and two hours later.

You will be asked to sit and wait between tests

If your blood glucose level is above the normal range at your fasting, one or two-hour test, you have gestational diabetes.

Women with an increased risk of gestational diabetes include those who:

  • are aged 40 years or over
  • have a family history of type 2 diabetes or a first-degree relative (mother or sister) who has had gestational diabetes
  • are above the healthy weight range
  • have had elevated blood glucose levels in the past
  • come from Aboriginal or Torres Strait Islander backgrounds
  • are from a Melanesian, Polynesian, Chinese, Southeast Asian, Middle Eastern or Indian background
  • have had gestational diabetes in a previous pregnancy
  • have polycystic ovary syndrome
  • have previously had a large baby (weighing more than 4.5kg)
  • are taking some types of antipsychotic or steroid medications
  • have gained weight too rapidly in the first half of pregnancy.

When diagnosed with gestational diabetes your doctor will refer you to see a diabetes educator to discuss what gestational diabetes is, how to manage it and to answer any questions you may have.

The diabetes educator will explain the importance of following up with a dietitian a week or so later to assess that your diet is nutritionally complete and discuss carbohydrates in your diet, to make sure you and your baby are healthy and well throughout the pregnancy.

Source: Diabetes NSW/ACT, NDSS