Gestational Diabetes

Introduction 

Gestational diabetes is a type of diabetes that affects women during pregnancy. Diabetes is a condition where there is too much sugar in the blood. Normally, the amount of glucose in the blood is controlled by a hormone called insulin. However, during pregnancy, some women have higher than normal levels of glucose in their blood and their body cannot produce enough insulin to transport it all into the cells. This means that the level of glucose in the blood rises.

How common is gestational diabetes?

Two to five in every 100 women giving birth has diabetes. Most of these women have gestational diabetes, and some have type 1 or type 2 diabetes.

Outlook

Gestational diabetes can be controlled with diet and exercise. However, some women with gestational diabetes will need medication to control blood glucose levels. If gestational diabetes is not detected and controlled, it can increase the risk of birth complications, such as babies being large for their gestational age. In most cases, gestational diabetes develops in the third trimester and usually disappears after the baby is born. However, women who develop gestational diabetes are more likely to develop type 2 diabetes later in life.

Gestational diabetes often doesn't have any symptoms, but you may:

- feel tired

- have a dry mouth

- be very thirsty

- wee a lot

- get recurring infections, such as thrush

have blurred vision

If you have any of these symptoms, tell your midwife or doctor.

Risk factors

You may be at increased risk of gestational diabetes if:

your body mass index (BMI) is 30 or more

you have previously had a baby who weighed 10lbs or more at birth 

you have a family history of diabetes/ one of your parents or siblings has diabetes

Your baby may be at risk of: 

stillbirth

health problems shortly after birth (such as heart and breathing problems) and needing hospital care

developing obesity or diabetes later in life

Diagnosis

The oral glucose tolerance test (OGTT) can be used to test for GDM. The current National Institute for Health and Care Excellence (NICE) guidance recommends that:Woman who have had GDM in a previous pregnancy should be offered early self-monitoring of blood glucose or a two-hour 75 g OGTT at 16-18 weeks, followed by a repeat OGTT at 28 weeks of pregnancy if the first test is normal.Women with other risk factors should have an OGTT at 24-28 weeks.

Treatment 

Your diabetic treatment is likely to need adjusting during your pregnancy, depending on your needs. If you take drugs for conditions related to your diabetes, such as high blood pressure, these may have to be altered.

It's very important to keep any appointments that are made for you, so that your care team can monitor your condition and react to any changes that could affect your own or your baby's wellbeing.

Expect to monitor your blood glucose levels more frequently during pregnancy. Your eyes and kidneys will be screened more often to check that they are not deteriorating in pregnancy, as eye and kidney problems can get worse. You may also find that as you get better control over your diabetes, you have more low blood sugar attacks. These are harmless for your baby, but you and your partner need to know how to cope with them. 

Controlling gestational diabetes

Gestational diabetes can often be controlled by diet. A dietitian will advise you on how to choose foods that will keep your blood sugar levels stable. You'll also be given a kit to test your blood glucose levels. If your blood sugar levels are unstable, or your baby is shown to be large on an ultrasound scan, you may have to take tablets or give yourself insulin injections.

Labour and birth

If you have diabetes, it's strongly recommended that you give birth with the support of a consultant-led maternity team in a hospital. 

Depending on how your pregnancy is going, you may be offered induction of labour or caesarean section, between 38 weeks and 40 weeks. Another option from 38 weeks is to wait for labour to start naturally but to have regular scans. These scans will check how your baby is doing and check the blood supply from the placenta. 

After the birth

Two to four hours after your baby is born, they will have a heel prick blood test to check whether their blood glucose level is too low. Feed your baby as soon as possible after the birth usually within 30 minutes to help keep your baby's blood glucose at a safe level. If your baby's blood glucose can't be kept at a safe level, they may need extra care. Your baby may be given a drip to increase their blood glucose. 

When your pregnancy is over, you won't need as much insulin to control your blood glucose. You can decrease your insulin to your pre-pregnancy dose or, if you have type 2 diabetes, you can return to the tablets you were taking before you became pregnant. Talk to your doctor about this. If you had gestational diabetes, you can stop all treatment after the birth. You should be offered a test to check your blood glucose levels before you go home and at your six-week postnatal check. You should also be given advice on diet and exercise.