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HealthInfo Canterbury

Diabetes in pregnancy

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You may already have diabetes or develop gestational diabetes during pregnancy. This means you need to be referred to the specialist diabetes team at Christchurch Women's Hospital. You can continue to receive care from your midwife, LMC or GP in the community as well.

Gestational diabetes

FDP pregnant womanAround 3.7% of pregnant women develop gestational diabetes mellitus (gestational diabetes). This happens because of the hormones the placenta makes during late pregnancy. These hormones make it harder to control blood glucose (sugar) levels. Some women can't make enough insulin to keep up with these changes, and their glucose levels rise.

When the mother's glucose (sugar) levels rise, so does the baby's, which can make it produce too much insulin. This can make the baby grow too much and has some other harmful effects.

Some women have a higher risk of getting gestational diabetes. This includes women who:

All pregnant women are offered an antenatal blood test early in their pregnancy. This includes the HbA1c test, which screens for diabetes.

Your lead maternity carer should screen you for gestational diabetes. This happens when you've been pregnant for 27 to 28 weeks, using a blood test called the polycose test. For this test, they will give you a drink containing glucose (sugar). They will then take a sample of your blood one hour later. If the test is high, you will need to have a second test, called the glucose tolerance test.

If your lead maternity carer thinks you might be getting diabetes after 28 weeks, they may screen you again later in your pregnancy.

Diabetes New Zealand has more information on gestational diabetes.

Type 1 diabetes

If you have type 1 diabetes you will be taking insulin to control your blood sugar levels. It is important to have good control of your sugar levels before becoming pregnant. This is to avoid unnecessary complications. Insulin is safe in pregnancy and you should keep using it.

See either your GP or diabetes specialist in the months before you plan to become pregnant if possible. You should also take a higher dose of folic acid than women without diabetes (5 mg daily). You will need a prescription from your doctor for this.

Type 2 diabetes

If you have type 2 diabetes you may be taking medication to control your blood sugar levels. It is important to have good control of your sugar levels before becoming pregnant. This is to avoid unnecessary complications.

See either your GP or diabetes specialist in the months before you plan to become pregnant if possible. This is so that they can make any necessary adjustments to your medication.

If you become pregnant unexpectedly, don't stop your medication. Make an appointment to see your GP as soon as possible.

Try to maintain a healthy weight both before and during your pregnancy. You should also take a higher dose of folic acid than women without diabetes (5 mg daily). You will need a prescription from your doctor for this.

  HealthInfo recommends the following pages

Written by HealthInfo clinical advisers. Last reviewed July 2019.

Sources

See also:

Understanding your HbA1c results

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