Gestational Diabetes (GDM)

Gestational diabetes is diabetes that develops during your pregnancy. For most women it develops in the second to third trimester when the body produces large amounts of hormones that help your baby grow. These hormones prevent your insulin hormone from meeting the extra needs in pregnancy. Insulin is the hormone that regulates your sugars levels.

With gestational diabetes, when there are higher levels of sugar in the mother bloodstream, this is passed through to the baby. The baby then must produce extra insulin to process this excess sugars. Insulin is a growth hormone and can then cause a larger baby.

Risk factors:

Some women are more likely than others to get gestational diabetes. You are at higher risk if any of the following apply to you:

• Your BMI is greater than 30
• You have a family history – one of your parents or siblings has it.
• You had GDM in a previous pregnancy
• You have a South Asian, Black, Caribbean or Middle East background.
• Have had a large baby previously

 

• Have had a previous unexplained stillbirth
• Have had glucose in your urine.
• Have had a scan recently to show a larger baby or polyhydramnios (extra fluid around the baby)

Testing

Your midwife will ask you about these risk factors at your booking appointment and offer you a test if any apply to you. You may also be offered a test if concerns are detected during your pregnancy.

Gestational diabetes is usually diagnosed by a test called an oral glucose tolerance test (sometimes shortened to OGTT). This test is usually done at 24 to 28 weeks pregnancy if you are identified to have a risk factor or earlier if you have had gestational diabetes before.

Why is diagnosing GDM important?

If gestational diabetes is not treated there is an increased risk of serious complications to you and your baby. You are more likely to have a large baby which means there is a greater chance of problems for you and your baby during the birth. You may need to have your labour induced and/or a caesarean section. Your baby is also more likely to have low blood glucose levels when he/she is born. Keeping your blood glucose at the right level reduces the chances of these problems. If you are diagnosed with gestational diabetes further information on these complications will be given by specialist midwives and obstetricians.

Treatment and management

Your care team will invite you in person for advice and information about gestational diabetes and how to stay healthy during your pregnancy. This should include information on a healthy diet, how to check your blood glucose levels and advice about taking regular exercise such as walking 30 minutes after a meal.

The treatment you are offered will depend on your blood glucose levels and your preference. For some women gestational diabetes can be improved by changes in the diet and doing more exercise. If these changes don't improve glucose levels medication will be offered. This may involve Metformin tablets or insulin injections.

The following videos have also been put together by a diabetes specialist midwife explaining gestational diabetes and the treatment provided at Queen's and King George maternity.