Gestational Diabetes

Pregnancy and diabetes
Gestational diabetes develops in women during pregnancy because the mother’s body is not able to produce enough insulin. Insulin is a hormone that enables the body to break down sugar (glucose) to be used as energy. Without sufficient insulin the amount of sugar in the blood rises. High blood sugar levels in the mother’s body are passed through the placenta to the developing baby. This can cause health problems.
Gestational diabetes usually begins in the second half of pregnancy, and goes away after the baby is born. This makes it different to the more common forms of diabetes which, once they occur, are permanent.


What causes gestational diabetes?
The hormones produced during pregnancy work against the action of insulin. Gestational diabetes can happen if the mother’s body can’t produce enough extra insulin to counteract this blocking effect.


Who is more likely to get gestational diabetes?
Women are more at risk if they:
• have a family history of type 2 diabetes
• are over the age of 35
• are obese
• have previously given birth to a large baby
• have previously given birth to a baby born with an abnormality
• have previously had a stillbirth late in pregnancy


How would I know if I had gestational diabetes and how is it is it diagnosed?
The symptoms of gestational diabetes are tiredness and excessive urination. Both of these symptoms are experienced by most pregnant ladies and therefore gestational diabetes may go unnoticed. It is normal to be tested for gestational diabetes in the latter part of the second trimester of pregnancy (24 to 28 weeks). Urine is routinely tested for sugar throughout pregnancy, and high blood sugar, if present, is usually detected between 24 and 28 weeks of pregnancy. The only way to confirm gestational diabetes is with a glucose tolerance test, which needs to be carried out after eight hours without food. The woman is given a solution of glucose to drink, and then blood samples are taken and analysed at different intervals to see how the body deals with the glucose over time.


What is the treatment of gestational diabetes?
The most important part of treatment is to control blood sugar levels. For many women, this means regular testing of blood sugar (glucose) levels, a carefully planned diet and regular exercise. Some women will require insulin injections. The extra insulin will not cross the placenta and will not affect the baby.

Does gestational diabetes go away?

Gestational diabetes usually goes away after pregnancy. But once you’ve had gestational diabetes, your chances are 2 in 3 that it will return in future pregnancies. In some women, however, pregnancy uncovers type 1 or type 2 diabetes. It is difficult to ascertain whether they are having gestational diabetes or are showing their diabetes during pregnancy.


Many women who have gestational diabetes go on to develop type 2 diabetes in the later years. There seems to be a relation between the tendency to have gestational diabetes and type 2 diabetes. Both conditions involve insulin resistance. If you have had gestational diabetes you should have a blood test to check for Diabetes six weeks after your baby is born and every year thereafter to ensure you have not developed Type 2 Diabetes.


Certain basic lifestyle changes may help prevent diabetes after gestational diabetes:

  • Weight loss- losing weight can help avoid developing type 2 diabetes. A Healthy BMI is 20 – 25.
  • Healthy eating habits can go a long way in preventing diabetes and other health problems
  • Staying active protects against weight gain and health problems.

Most women with diabetes have a normal pregnancy resulting in a healthy baby. However, having diabetes does increase the chances of complications for both mother and baby.

gestational Diabetes and Overweight Children


Planning and preparing for a pregnancy with your diabetes team can substantially reduce that risk.


Professor Fidelma Dunne and her team explain the risks involved with diabetes in pregnancy and how to reduce these risks to ensure the best possible outcome for both mother and baby with type 1, type 2 and gestational diabetes.
See for invaluable information and videos on pregnancy and diabetes.


Download our booklet on Gestational Diabetes


To read Yvonne Moloney’s, a Registered Advanced Midwife Practitioner (RAMP) Diabetes with the University of Limerick Hospitals Group, featured piece on Gestational Diabetes in our 2022 members magazine, click here.

Overweight and obesity, diabetes in an immediate family member and older age are all risk factors for developing diabetes during pregnancy, write Yvonne. Read the full article


Updated July 2020