Gestational Diabetes is the name given to diabetes which can occur during pregnancy. It occurs when the level of glucose in the blood becomes too high. During pregnancy extra hormones can increase the demand for insulin, the hormone that controls the glucose levels in the blood. Sometimes there is not enough insulin to control the blood glucose level and this can lead to gestational diabetes.
Regular monitoring by your midwife at your antenatal appointments should mean that regular blood samples are taken, which are screened for glucose. If these come back high you will be asked to take a glucose load test. In this test you will have to fast overnight and drink a glucose solution in the morning prior to another blood test being taken exactly 2 hours after drinking it. A diagnosis is made when the blood glucose level is 7.8 mmol/l or above two hours after the test.
You are more at risk from suffering from gestational diabetes if you:
- Have a family history of type 2 diabetes
- Had an unexplained still birth or neonatal death in previous pregnancy.
- Have a BMI (body mass index) above 30kg/m2
- Had a very large infant (9lb or more) in a previous pregnancy
- Are South Asian, Black Caribbean and middle Eastern
However one in five pregnant women will be diagnosed with gestational diabetes, especially in the last trimester of their pregnancy. But you can control your glucose levels and manage your diabetes by following an eating plan.
It is important to follow a balanced diet when you are pregnant to ensure you and your baby get all the nutrients you require. You do not need to eat for two as you do not require much more food than you would normally require (approx 200 extra calories a day). However, you should not aim to lose weight during your pregnancy either. It is important to keep your weight stable and to eat the right kinds of food.
Food that cause your blood glucose levels to rise are carbohydrates as these are broken down into sugar in the body (glucose). You need a regular supply of carbohydrate to fuel your body and insulin that you produce helps you to use this glucose for energy. The amount of glucose produced depends on the amount of carbohydrate eaten. It is therefore important to spread carbohydrate foods evenly over the day and avoid large portions.
Foods containing carbohydrates include:
- All types of bread and bread products
- Fruit and fruit juices
- Snacks like biscuits, cakes, crisps, cereals
- Pies and pasties
- Sugar (glucose, fructose)
- Milk, yogurt and ice cream
- Pulses (peas, beans and lentils)
- Grains (pasta, rice, couscous)
- Cereal based products
You should try to avoid too much weight gain and avoid large portions of carbohydrates. Eat regular meals. Try to distribute your carbohydrate intake evenly at each meal.
Blood glucose monitoring
Blood glucose monitoring will help you to understand how different carbohydrate foods and portions affect your blood glucose levels. You may be issued a blood glucose monitoring system to take your own measurements. A simple finger prick blood sample is taken and measured prior to meals and one hour after eating.
A diary can be keep of the measured glucose levels to help build up a picture of which foods are more likely to cause spikes in your glucose levels. You are aiming for a measurement of less than 7.8 mmol/l. It can be difficult to keep below this figure, especially breakfast, and you will need to modify your eating habits. You may find it beneficial to have two smaller portions spaced over several hours rather than one portion.
Starchy foods with a low Glycaemia index (GI) release glucose very slowly into the blood, helping you to control your blood glucose level. Avoid foods with a high glycaemia index.
Low GI foods:
- Wholegrain or mixed grain breads (granary, rye, linseed)
- Pasta, buckwheat and bulgar wheat
- Most vegetables
- Low fat milk, diet yogurt
- Apples, apricots, citrus, cherries, grapes, mangos, pear, plums, prunes, kiwi, strawberries
- Sweet potato
- Oatmeal biscuits
- Dark chocolate, peanuts, cashew nuts
Medium GI foods:
- Pitta, muffins, crumpets
- Basmati rice, couscous, quinola
- Beans and pulses; ice cream, low fat custard
- Apricot, banana, pineapple, fruit juice, mixed dried fruit, dried figs, sultana and raisins
- New potatoes, boiled potatoes
- Shredded wheat
- Rich tea, digestives, shortbread
- Honey, reduced sugar jams
High GI foods:
- White breads, wholemeal bread, baguettes, bagels; brown rice, white rice, rice cakes, crackers
- Beetroot and broad beans
- Soya milk, rice milk
- Dried dates, melon, jam and marmalade
- Chips, instant potato, roast potato, mashed potato
- Rice krispies, cornflakes, sugary cereals, sultana bran
- Crackers, custard creams, bourbon biscuits
- Sugar, glucose tablets, soft drinks, sweets.