What is Gestational Diabetes and How Will It Affect My Baby?

Gestational diabetes, also known as ‘pregnancy diabetes’ is diagnosed when higher than normal blood glucose levels first appear during pregnancy.

You are at risk of developing gestational diabetes if you:

  • have a family history of type 2 diabetes
  • are over 30 years of age
  • are overweight
  • are from an indigenous Australian or Torres strait islander background
  • are from a Vietnamese, Chinese, Middle Eastern, Polynesian or Melanesian background
  • have had gestational diabetes during previous pregnancies.

From 3-8% of pregnant women will develop gestational diabetes around the 24th to 28th week of pregnancy, however, some may be earlier. In pregnancy the placenta produces hormones that help the baby grow and develop. These hormones also decrease the action of the mother’s insulin. This is called insulin resistance and because of this insulin resistance, the need for insulin in pregnancy is two or three times higher than normal. Consequently during pregnancy, the mother needs to produce higher amounts of insulin to keep blood glucose levels within the normal range. If her body is unable to produce more insulin to meets her body’s needs then gestational diabetes develops.

During pregnancy, glucose crosses the placenta from mother to baby to meet the energy needs of the growing baby, so if the mother’s blood glucose levels are higher than normal, extra glucose will cross the placenta to the baby. The baby makes more insulin to deal with the extra glucose. Insulin makes the baby grow larger more quickly. If the mother’s glucose levels remain high the baby may become larger than normal which can lead to problems during and after birth.
It is important to keep blood glucose level within the recommended range. This helps reduce the baby’s risk of being overweight in childhood and developing type 3 diabetes later in life.

Your Obstetrician will ensure that you receive the support of health professionals such as a Diabetes Educator, Dietitian or Diabetes Specialist, to provide necessary guidance and education in the management of this condition during your pregnancy.

Management of Gestational Diabetes

Some advice you may receive will include advice about a healthy diet during pregnancy; regular monitoring of blood insulin levels; physical activity; insulin injections if required and education about Diabetes and its management to ensure that you and the baby have a healthy outcome.

After the Baby is Born

Following delivery your baby’s blood glucose levels are measured to ensure their blood glucose is not too low. If it is, this can be treated by feeding your baby breastmilk or formula. Breastfeeding is encouraged.

Blood glucose levels are measured several times daily to ensure these are within the normal range. Maternal blood glucose levels usually return to normal, but there is a known increased risk for type 2 diabetes for you in the future.

Six to eight weeks after the baby is born an OGTT is done to ensure the mother no longer has diabetes.

If you have had gestational diabetes your baby will NOT be born with diabetes, but they may be at risk of developing type 2 diabetes later in life.

Future Pregnancies

A glucose tolerance test (OGTT) will be performed early in any subsequent pregnancies to make sure that blood glucose levels are within the normal range. If the test is normal then a repeat OGTT will be done usually between 22 and 28 weeks gestation. Adherence to the guidelines suggested by the supporting health professionals will assist in avoiding a recurrence of gestational diabetes.