Diabetes in Pregnancy

Gestational diabetes mellitus (GDM) is a specific type of diabetes that only occurs during pregnancy. It is temporary and goes away after the birth of your baby. Approximately 15-20 % of pregnant women will develop gestational diabetes during pregnancy. However, if it is found in early pregnancy, it may be possible that it is pre-existing diabetes. Diabetes can have significant effects for both you and your baby if not well controlled.

You have an increased risk of developing GDM if you:

  • are aged over 30
  • have a family history of Type 2 diabetes
  • are overweight
  • have had diabetes in a previous pregnancy
  • have previously had difficulty carrying a pregnancy to term
  • have previously birthed a baby weighing more than 3.45 kg

Following a healthy diet, having a healthy weight gain during pregnancy and exercising regularly will help to minimise your risk of developing GDM.

How do I know if I have GDM?

All pregnant women are screened for diabetes. This involves an oral glucose tolerance test (OGTT) at booking and at 20 weeks of pregnancy. We may perform one more at 28 weeks of pregnancy. A blood test is taken before, and two hours after a sugary drink with 75 gms of glucose (Nutriright). If more than 120 mg/dl, you will be followed up further with diet advice. If the level is more than 140 mg/dl, you will be asked to see us in the combined diabetes clinic for appropriate management.

How is GDM treated?

The aim of treatment is to maintain your blood glucose levels within a normal range for the rest of your pregnancy. For most women this can be achieved by following a healthy diet—

  • Avoid sugars and sweets
  • Avoid instant and outside foods
  • Do not drink fruit juices and too many fruits high in sugar such as grapes, mangoes, pomegranates and bananas
  • Eat 3 meals and snacks daily. Wait 2 to 3 hours between meals and snacks
  • Do not eat fruit for breakfast. Eat fruit for snacks
  • Do not eat dry cereal (like cornflakes) for breakfast
  • Eat more cooked or raw vegetables

However, consulting our dieticians will help you plan your meals better depending on your specific needs.

Approximately one in 10 women with GDM will require insulin injections during pregnancy to maintain normal blood glucose level.

How does diabetes affect my baby?

Glucose (sugar) crosses the placenta so your baby is exposed to your higher glucose levels. This stimulates your baby’s pancreas to produce more insulin—it is the extra insulin that causes your baby to grow bigger and fatter. It may also make labour and birth more difficult. Diabetes in pregnancy is associated with increased risk of miscarriage, preterm labour, blood pressure problems, overweight unhealthy babies, caesarean section and also sudden intrauterine demise.

Your baby will be monitored closely in the first few days after birth. It can take several days for their body to adjust and their own blood glucose levels may drop. Your baby’s sugars will be tested regularly until their levels remain within normal range.

You can help your baby by:

  • controlling your sugars during pregnancy which may require home blood glucose monitoring with glucometer and maintaining a sugar profile
  • breastfeeding within one hour of birth and continuing to feed, at least every three hours, until your milk comes in (this usually occurs on the third day after birth)

What happens after the birth of my baby?

Usually the GDM goes away after the birth of your baby. However, there is a 40 per cent chance of developing GDM in your next pregnancy and an increased chance of developing Type 2 diabetes later in life. You will be asked to repeat your glucose tolerance test six to eight weeks after your baby’s birth. If this test is in the normal range, you will be asked to check your blood glucose levels every one to two years with your family doctor. Following a healthy diet, maintaining a healthy weight and exercising regularly will help to minimise these risks.