Having a Glucose Tolerance Test in Pregnancy

Please read the followign information carefully. It is important that you take note of any instructions or advice given.

Thisinformation is designed to give you information about a glucose tolerance test (GTT) which has been booked for you. If you have any questions or problems that are not answered in this booklet please ask your doctor or midwife.

Why am I being tested for diabetes?

An excess of glucose in the mother’s blood may mean that you are not metabolising (using) your glucose efficiently. In some cases this may cause a condition called Gestational Diabetes.

If this condition is suspected it may be necessary to perform a test called a Glucose Tolerance Test (GTT). This will see if you are metabolising your blood glucose efficiently.

If it is considered necessary for this test to be performed the doctor/midwife will discuss it with you. If you give your consent an appointment date will be given.

Who is tested for diabetes in pregnancy?

In Pregnancy, a GTT may be performed for one of the following reasons:-

• BMI (body mass index over 30)
• Previous baby over 4.5 kg (10lbs)
• Previous history of gestational diabetes
• First degree relative with diabetes (parent or sibling)
• Women from high-risk ethnic group (South Asian, Black Caribbean, Middle Eastern)
• Polycystic Ovarian Syndrome (PCOS)
• Large baby or extra fluid around the baby on scan in current pregnancy
• Previous stillbirth
• Women who take antipsychotic medication Clozapine/Olanzapine/Quetiapine

When & how?

The test is usually performed in the morning in Antenatal Clinic at Harrogate District Hospital. It may also be performed at Ripon Hospital antenatal clinic. An appointment will be given to you.

You must fast for this test, so please do not eat or drink anything other than water from 10 pm the night before.

Please bring a sandwich to eat once you have completed the test. If you usually take any medication please discuss this with your doctor or midwife before the test.

What happens when I go for the test?

On arrival you will have a sample of blood taken and then you will be given a glucose drink. Following this, you will be asked to rest. You are welcome to wait in the antenatal clinic, however please make sure you return to the blood test department after 2 hours, when your second sample is due. You may wish to bring something to read to help you pass the time.

When do I get my results back?

If your results are within the normal range you will not need any further investigations. Your results will be given to you at your next appointment.

If your results show that you have Gestational Diabetes you will be referred to the Joint Diabetes & Obstetric Team. This consists of a Consultant Diabetologist, an Obstetrician, Diabetes Specialist Nurse, Dietitian and Midwife. You will be seen at the earliest opportunity.

Next steps?

You will be given advice on diet and shown how to monitor your blood glucose levels. Some women may have to take tablets and/or insulin to control the blood glucose levels.

There will also be additional hospital antenatal appointments you will have to attend. These may include additional ultrasound scans to monitor your baby’s growth.

Contact details:-

Diabetes Centre Harrogate District Hospital Lancaster Park Road Harrogate HG2 7SX

www.hdft.nhs.uk Diabetes

Specialist Nurses Tel: 01423 555345

Maternity Single Point of Contact: 01423 557531

Gestational diabetes

This information is for you if you want to know about Gestational Diabetes or have recently been diagnosed with Gestational Diabetes.

What is Gestational Diabetes?

Gestational Diabetes is a type of diabetes which occurs during pregnancy. The exact cause is not known but it is thought the body cannot produce enough insulin to meet the extra needs of pregnancy.

Insulin helps us turn glucose into energy.

We get glucose from the carbohydrates foods in our diet such as:

• Starchy foods e.g. bread, rice, pasta, potatoes, cereals
• Sugar and other sweet foods e.g. biscuits, cakes, sweets

A lack of insulin can result in high blood glucose levels.

What are the risk factors?

• Previous gestational diabetes
• Previous larger baby over 4.5Kg
• Body Mass Index (BMI) over 30Kg/m2
• If you have an immediate family member with diabetes (parent, brother or sister)
• If you are of South Asian, Chinese, African-Caribbean or Middle Eastern origin
• Previous stillbirth
• Polycystic Ovarian Syndrome (PCOS)
• Large baby or extra fluid around the baby (diagnosed on scan)
• Women who take antipsychotic medication- Clozapine/Olanzapine/Quetiapine

How will it affect me and my baby?

Most women who develop gestational diabetes have healthy pregnancies and healthy babies but occasionally gestational diabetes can cause serious problems, especially if it is not recognised or treated.

If your blood glucose levels are high, the chances of you having an induced labour or a caesarean birth are increased.

The risks to your baby are:

• Being bigger than average · Shoulder dystocia (where your baby’s shoulder gets stuck during birth)
• Stillbirth or the baby dying at or around the time of birth. This is uncommon.
• Needing additional care once they have been born, possibly in a neonatal unit
• Being at greater risk of developing obesity and developing type 2 diabetes in later life.

Controlling your levels of blood glucose during pregnancy and labour reduces the chances of these complications for you and your baby.

If your blood glucose levels are not well controlled during pregnancy it can cause the baby to grow larger than normal, which in turn can make delivery difficult.

Gestational diabetes can also increase the risk of stillbirth, can raise blood pressure during the pregnancy (pre-eclampsia) and can cause preterm (early) labour.

After the birth, if your blood glucose has not been well controlled there may be problems for your baby immediately after delivery, such as:

• Needing help to breathe
• Having very low blood glucose levels
• Developing jaundice

These risks can be significantly reduced with the support of your health care team.

What can I do whilst pregnant?

You can help yourself by monitoring your blood glucose levels, taking regular exercise and implementing a healthy diet.

Blood glucose monitoring

You will be given a blood glucose monitoring meter which the Diabetes team will show you how to check your blood glucose and be given a diary to record the results. You will be asked to check your blood glucose levels post meals.

The blood glucose levels should ideally be:

Fasting (when you get up in the morning) and pre-meal: 4.0-5.3 mmol/L

1 hour after a meal: Less than 7.8 mmol/L

2 hours after a meal: Less than 6.4 mmol/L

Exercise

The most important treatment for gestational diabetes is a healthy eating plan and exercising regularly. Walking for 30 minutes after a meal can help with controlling your blood glucose levels. Gestational diabetes usually improves with these changes. You should have an opportunity to talk to a healthcare professional about choosing foods that will help to keep your blood glucose at a healthy and stable level.

Try to increase your levels of activity through more walking or swimming. Check with your doctor first if you have any other pregnancy complications.

Weight

It is a myth that you are eating for two. Your calorie requirements increase very little. If additional energy is required it is usually only about 200 extra calories a day during the last 3 months (1 whole-wheat pitta with 2 tablespoons of hummus).

The average weight gain during pregnancy is just under 2 stones (12kg). The amount of weight you are advised to gain depends upon your pre-pregnancy weight.

Principles of healthy eating with Gestational Diabetes

The diet recommended for women with Gestational Diabetes is a healthy diet similar to that recommended for the general population with more emphasis on low glycaemic index carbohydrates.

Carbohydrate is the main type of food which affects your blood glucose levels.

During digestion, carbohydrate foods are broken down into glucose, which is absorbed into the blood stream causing a rise in your blood glucose level.

Blood glucose is the body’s main source of fuel and requires insulin to move it from the blood stream into the body tissues where it is used for energy.

Main Dietary Principles for Gestational Diabetes

1. Include starchy carbohydrate foods at every meal to help regulate blood glucose levels. However the more carbohydrate foods you eat the higher your blood glucose levels will go. It is recommended that you consume a diet that includes foods that have a low glycaemic index. These types of foods allow glucose to be absorbed at a much slower rate which can stop the peak in blood glucose levels after meals. However it is important to still consider portion sizes.

The following information shows foods having a low glycaemic index:

Lower Glycaemic Index (GI) Foods

Choose lower GI foods most of the time as they release glucose more slowly, helping to keep blood sugar levels more stable. Good choices include wholegrain or mixed grain breads such as granary, rye and linseed bread. For breakfast, choose oat-based cereals such as porridge, sugar-free muesli or bran-rich cereals like All Bran®. Pasta and noodles are lower GI options, while basmati rice is a better choice than other types of rice. Peas, baked beans, kidney beans, lentils and nuts are excellent lower GI sources of carbohydrate and protein. For potatoes, choose sweet potatoes, new potatoes with their skins on or yams. Most fruit is suitable, particularly if it is not over-ripe, including apples, pears, citrus fruits, plums, grapes and cherries. Vegetables such as green vegetables, salad vegetables, carrots, plantain and yam are all lower GI choices. Milk, plain yoghurt and diet or light yoghurts are also suitable dairy options.

Medium Glycaemic Index (GI) Foods

Medium GI foods can be included in moderation. These include pitta bread, muffins, crumpets and croissants. Couscous and rice noodles are medium GI alternatives to pasta, while both white and brown rice fall into the medium GI category. Boiled potatoes and French fries also have a medium GI. Fruits such as dried fruit, apricots, peaches, bananas and pineapple have a moderate effect on blood glucose levels. Beetroot and sweetcorn are medium GI vegetables.

High Glycaemic Index (GI) Foods

High GI foods are digested quickly and are more likely to cause a rapid rise in blood glucose levels, so they are best eaten less often. These include white, brown and wholemeal bread, baguettes and bagels. Many maize- or wheat-based breakfast cereals, including cornflakes, Weetabix®, Coco Pops®, Sugar Puffs®, Honey Loops® and cereal bars, are also high GI choices. Instant potato, jacket or baked potatoes and mashed potatoes have a high GI. Broad beans are a higher GI pulse, while fruit juices, watermelon and lychees are higher GI fruit choices. Parsnips and pumpkin are higher GI vegetables, and fruit yoghurts containing added sugar are higher GI dairy options.

2. Reduce your sugar intake

Reduce your sugar intake by limiting foods and drinks high in added sugar. This includes all types of sugar (such as white, brown, demerara, muscovado and glucose), as well as sweeteners that contain sugar. Try to avoid sugary drinks like squash, cordial, fizzy drinks and Lucozade, along with ordinary jams, marmalade, honey, syrup, treacle and lemon curd. Tinned fruit in syrup, sweets, chocolate, confectionery, ice lollies, sweet biscuits and cakes are also high in sugar and should be limited.

Choose lower-sugar alternatives where possible. Artificial sweeteners can be used instead of sugar, and sugar-free or no-added-sugar drinks are preferable to sugary drinks. Opt for reduced-sugar jams or pure fruit spreads, and choose fruit tinned in natural juice or water instead of syrup. Sugar-free jelly, reduced-sugar desserts, diet yoghurts and milk puddings sweetened with artificial sweeteners are suitable alternatives. Plain biscuits, such as digestives, Rich Tea, Marie biscuits and oatcakes, are also a better choice than sweet biscuits and cakes.

3. Carbohydrate free Snacks

• Mixed salad vegetables
• Celery sticks with small amount peanut butter/ ¼ pot Tzatziki dip / ¼ pot guacamole
• 1 avocado
• Olives
• Poached / boiled / scrambled (no milk) eggs
• 1 small omelette with mushroom / ham / pepper
• Chicken strips/wings/drumsticks
• Prawns or seafood
• Tinned salmon / sardines / tuna / mackerel
• Ham/turkey/roast beef/salmon slices/pork /lamb
• Kebab skewers with roast vegetables (courgette/onion/pepper – not potato)
• Small portion of tofu
• 50g Walnuts / Brazils / Pecans / Macadamias / Coconut flakes
• 30g Cashews / Peanuts / Pistachios / Almonds/Sesame seeds
• 20g pumpkin seeds / sunflower seeds / mixed seeds
• Unsweetened coconut flakes
• Shiratake noodles (Konnyaku) from oriental supermarkets or’ Zero Noodles’ from health food shops
• Pepperoni sticks
• Sausages/frankfurters
• Sugar-free jelly
• No added sugar ice pops
• Cocoa hot drink – 1 level tablespoon unsweetened cocoa powder made with hot water and cream

Low Carbohydrate snacks

• Small pot of diet yogurt (<15g carbohydrate) or bowl of Greek yogurt (200-250g pot)
• Fruit – e.g. 1 medium apple/1 small banana/2 small fruits e.g. plums, kiwis or 150g berries +/- wedge of cheese/nuts
• 1-2 Oatcakes/Ryvita/1 slice wholegrain bread with hummus/peanut butter/cottage cheese/mashed avocado/mashed sardines
• Sachet of cup a soup (<15g carbohydrate)/homemade soup
• 1 plain biscuit e.g. Digestive/Hobnob
• Packet of wotsits/french fries/quavers
• 200ml glass of semi-skimmed milk
• 30g plain popcorn

4. Try to eat lean protein foods such as chicken, lean meat, eggs and fish. Try to eat two portions of fish per week, one portion being an oily fish. One portion is roughly 100g (4oz). Many of the oily fish can be bought fresh or tinned. The following are examples of types of oily fish:

• Mackerel
• Kippers
• Salmon
• Pilchards
• Tuna (fresh/frozen, not tinned)

You should avoid shark, marlin and swordfish. These types of fish contain high levels of mercury, which can affect your baby’s developing nervous system.

5. Aim for 5 portions of fruit and vegetables daily, spread out fruit during the day, a portion at a time – a portion is the size you can fit in the palm of your hand. Aim to bulk your diet in more vegetables than fruit.
6. Include milk and dairy foods. These are an important source of calcium aim to eat 3 portions a day. (1 yoghurt, 1/3 pint milk, 30g cheese, 1 bowl milk pudding /custard). Low fat versions have the same amount of calcium.
7. Cut down on salt. Use less in cooking and eat less salty foods for overall good health.
8. Avoid special diabetic products, diabetic biscuits and chocolate. They contain the same amount of fat and are not significantly lower in calories than their non-diabetic equivalents. They may also be sweetened with a substance called ‘Sorbitol’ which may cause diarrhoea.
9. Alcohol. Drinking too much alcohol can harm your baby. You should drink as little as possible and ideally stop drinking altogether until after the baby is born.

If dietary measures are not sufficient to control your blood glucose at normal levels, the diabetes team may recommend that you are treated with tablets called Metformin. Some women may need insulin injections as well.

Do you suffer with nausea?

It may be helped by:-

• Eating dry biscuits or dry toast in the morning
• Avoiding fried and spicy foods
• Eating regular meals with snacks in between

Do you suffer with heartburn?

Heartburn can become a problem as pregnancy advances. To avoid this:

• Chew food thoroughly and do not lie down after eating
• Avoid foods that are hard to digest such as spicy, pickled and fried foods
• Change your daily meal pattern – avoid large meals – try 6 smaller meal a day rather than 3 large. Sleep in a more upright position
• Gaviscon® liquid may help – ask your doctor about this

What happens after delivery?

You will be given information before you go home after you have had your baby about follow up, screening for diabetes, and future risks.