Gestational diabetes

Diabetes with first onset or recognition during pregnancy. About 5 % of women develop diabetes during their pregnancy usually in the 4th to 5th month. Most women who develop this condition do not have any symptoms of diabetes and the condition is most often picked up during routine ante-natal tests. Symptoms such as excessive thirst and tiredness can also indicate a problem which is then confirmed by blood tests. It is possible that the individual will go on to develop Type 1 or Type 2 diabetes but diagnosis is not generally made during the pregnancy. About 50% of persons with gestational diabetes will go on to develop Type 2 diabetes later in life.

If a woman has gestational diabetes in one pregnancy, this does not mean that she will do so in subsequent pregnancies. However, this person would be considered high risk for developing it in each subsequent pregnancy. In fact, as you get older your chances of developing the problem increases. Gestational diabetes is controlled by diet, regular exercise and insulin if necessary. Although insulin injections may seem frightening, modern appliances are less painful than traditional needles. Tablet treatment for diabetes is not an option during pregnancy. This will mean that the pregnancy will be more closely supervised and the person will have more ante-natal visits.

The diagnosis of gestational diabetes is important because it can affect the health of the mother and the baby. Some of the potential problems include, increased risk of premature birth, increased risk of pre-eclampsia (complication of high blood pressure in pregnancy), more difficult birth if the baby is large, breathing problems for the baby after birth and a too large or small baby. All of these problems can be reduced by correct control of the blood sugar. Even when they do occur, they are easily diagnosed and treatment is available.

Article from Identity – September 2002

Gestational Diabetes is defined as Diabetes first discovered during pregnancy. This type of diabetes behaves like Type 2 diabetes in some ways e.g. your body becomes resistant to insulin. Every cell in the body needs glucose for energy and insulin is needed to allow glucose into the cells. This means that insulin resistance causes glucose to stay in the blood circulation for longer than normal. Pregnancy hormones increase insulin resistance.

Gestational Diabetes is usually diagnosed in the last three months of pregnancy but may occur at any stage. The baby tends to put on its main body weight towards the end of pregnancy. High blood glucose levels in the mother during pregnancy make the baby gain extra weight and may lead to difficulty at delivery time e.g. increased risk of Foeceps delivery or Caesarian Section. In most instances the mother’s blood glucose levels return to normal after the baby is born.

Who is at risk?

•        Age 40 or more
•         History of diabetes in the immediate family
•        Previous unexplained stillbirth
•        Weight 100k at first antenatal visit
•        Previous baby 4.5 kilos or more at term
•        Glucose in a urine sample ( glycosuria)
•        Excess fluid around the baby in current pregnancy (polyhydramnios)
•        Excess weight gain of baby in current pregnancy (macrosomia)
•        Long term steroids

Gestational diabetes is on the increase for a variety of reasons.

Increased weight – in Ireland, 18% of the Irish population are obese in comparison with 6% in 1980. This has been influenced by-

Sedentary lifestyle – too little exercise. The benefit of exercise is well documented including an increased feeling of well-being and more efficient glucose uptake in the body i.e. better blood glucose levels.

More refined foods in the diet - not enough wholegrains and fibre. In general many people are not eating a healthy, balanced diet. Fibre rich foods are absorbed more slowly and tend not to cause sudden rises in blood glucose levels.

Testing for Gestational diabetes may by carried out in several ways, depending on which hospital you attend.

Firstly a screening test -

•        Glucose Challenge Test ( G.C.T.) – a sweet drink (50 g carbohydrate) followed by a blood sugar test after one hour. If the result is normal, no further action is taken.

If the result is abnormal –a more detailed diagnostic test is carried out

•        Glucose Tolerance Test (G.T.T.) - is done by fasting for 12 hrs, having a blood sugar test, a sweet drink (100g carbohydrate) and a blood test 1 hr, 2 hrs and 3 hrs later.

An abnormal glucose tolerance test diagnoses diabetes.

So, you have Gestational diabetes – what happens now? In my own experience many women with this diagnosis complain of extreme tiredness – more than could be explained by their stage of pregnancy. Very few complain of increased thirst and it is common to need to pass urine frequently in later pregnancy anyway. When blood glucose levels are back to normal there is usually a sense of having more energy and feeling much better overall. It is very reassuring that whatever is needed to achieve good glucose control leads to a feeling of being energised.

An appointment for the next Diabetes clinic is made - usually within one week. In some hospitals, this clinic is combined with the antenatal clinic, which is more convenient for pregnant women. While routines will vary slightly in different hospitals, the following is an account of one well tried and tested system.

Ideally the team that you will meet includes a Consultant Diabetologist, a Diabetes Midwife/Nurse Specialist, a Dietician and an Obstetrician but provision of services varies greatly throughout the country.

First visit to this clinic involves assessment by the diabetes midwife/nurse specialist and an explanation about Gestational diabetes and its effect on your pregnancy. The clinic routine is also outlined and any questions or fears are addressed. This may be a time of great anxiety and sometimes a sense of misplaced guilt so care should be taken to provide the emotional support that may be needed at this time.

The Diabetologist will see and assess your test results and will decide on your follow up care. He will reinforce the importance of the recommended lifestyle changes and will usually ask to review you in one week.

High blood glucose levels are not healthy for the baby and pregnancy hormones increase insulin resistance, so the first change in lifestyle to be suggested is to eat healthily as your body may no longer be able to cope with sweet foods or large portions at mealtimes. The recommended blood glucose (plasma glucose) levels should be <5 mmol/l before a meal and <7 mmol/l one hour after a meal.

The Dietician will take a detailed history of eating habits and preferences and will work out an individual eating plan with you at this time to aim for a well balanced diet. Normal healthy eating is advised, with the recommendation that a mid-morning, mid-afternoon and bed-time snack are included as part of the overall meal plan. Food samples are sometimes used to demonstrate recommended portion sizes. The inclusion of some carbohydrate e.g. bread, pasta, rice, potatoes or breakfast cereals at each main meal is advised as part of a balanced diet.

Exercise helps to lower glucose levels so walking or swimming regularly are very beneficial, taking into account the stage of pregnancy. Some exercise every day is better than lots of exercise on the weekend. In the later stages of pregnancy, care needs to be taken to exercise within your limitations, or taking medical advice if there are any other health problems.
Having received the relevant advice an appointment for one week is made. You will be asked to fast from midnight and to attend the Diabetes clinic at 09.00 you have now joined the ‘Breakfast club’.
•      A fasting blood sugar test is taken -,
•       Followed by breakfast and
•      A further blood test one hour later.

Providing these levels are normal, women are reviewed fortnightly in this way and also have an antenatal check up (depending on the stage of pregnancy). As long as the baby’s weight gain is normal and the mother’s blood glucose levels remain satisfactory, the expectation would be that labour should proceed normally.

Even with careful eating and exercise, sometimes blood glucose levels remain higher than desired. For these women it may become necessary to have insulin injections for the rest of the pregnancy. This usually involves a few days in hospital to learn all that is involved in adjusting to the lifestyle changes needed. In those hospitals with a diabetes midwife/nurse specialist, he/she provides continuity between the clinic, the person with diabetes and the hospital ward, which is really reassuring for the woman involved at this stressful time. As soon as the baby is born, the mother no longer requires insulin injections and her glucose levels usually return to normal within the first 48 hrs. The baby may need to have blood glucose levels checked for the first two days until he/she is feeding well. This is usually done at ward level so that mother and baby are kept together. Breast feeding is recommended as research shows that breast fed babies are less likely to develop diabetes in the future and it also helps to keep the mother’s glucose levels under control.

When the baby is six weeks old, a Glucose Tolerance Test is carried out on the mother to ensure that all is well. Developing Gestational Diabetes means a 60% risk of developing Type 2 diabetes within 5 years after diagnosis so advice is given to maintain a healthy lifestyle and to plan future pregnancies ensuring that glucose levels are normal before conception. High blood glucose levels in the first few weeks of pregnancy increases the risk of both heart defects and spina bifida.

While being told that you have a condition that may affect your baby’s wellbeing is very stressful, it is a condition that responds well to lifestyle changes and careful monitoring. It is a tribute to each mother and a testament to the power the human spirit that they cope so well with the necessary adjustments to everyday life.

Ms. Anna Clarke Health Promotion and Reserach Manager, Diabetes Federation of Ireland

APP/KOL/AC 30/07/2008

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