Gestational Diabetes

Gestational diabetes is diabetes that develops during pregnancy. It’s usually diagnosed from a blood test 24 to 28 weeks into pregnancy.

Countries such as the UK, approximately 16 out of every 100 women will develop gestational diabetes. Women with gestational diabetes don’t have diabetes before their pregnancy – and it usually goes away after giving birth.  But, in some women, diabetes may be diagnosed in the first 12 weeks of pregnancy –which is called the first trimester. If this is the case, they probably had diabetes before they got pregnant – and it won’t go away after giving birth.

What causes gestational diabetes?

Lots of changes happen to your body during pregnancy.

Along with the physical signs, the hormones you produce can make it hard for your body to use insulin properly. This puts you at an increased risk of insulin resistance, and some women can’t produce enough insulin to overcome it. This makes it difficult to use glucose (sugar) properly for energy, so it stays in your blood and the sugar levels rise. This then leads to gestational diabetes.

Who's at risk of gestational diabetes?

At your first antenatal appointment – also known as your booking appointment – a healthcare professional should check if you’re at risk of gestational diabetes.  They should offer you a test for gestational diabetes if you have any of these risk factors:

  • are overweight or obese
  • have had it before
  • have had a very large baby in a previous pregnancy – 4.5kg/10lb or more
  • have a family history of diabetes – parent or sibling
  • have a South Asian, Black or African Caribbean or Middle Eastern background.

Women can reduce their risk of developing gestational diabetes by managing their weight, eating healthily and keeping active before pregnancy. Having gestational diabetes increases your risk of developing it again in future pregnancies. It also increases your risk of developing Type 2 diabetes later in life, but there are lots of thing you can do to reduce your future risk.

Signs of gestational diabetes?

You may have been shocked to find out that you have gestational diabetes – many women have no noticeable symptoms.  As some of the signs of diabetes are like symptoms experienced in pregnancy anyway, most cases are diagnosed during screening for gestational diabetes. This is called an Oral Glucose Tolerance Test, also known as an OGTT. The OGTT is done when you’re between 24-28 weeks pregnant. If you’ve had gestational diabetes before, you’ll be offered an OGTT as soon as possible after your booking appointment, and another OGTT between 24-28 weeks if the first test result is normal. Speak to your doctor if you're worried about any of the symptoms you're experiencing.