What is gestational diabetes?
Diabetes that develops during pregnancy is known as gestational diabetes. It occurs because your body cannot produce enough insulin (a hormone important in controlling blood glucose) to meet its extra needs in pregnancy. This results in high blood glucose levels. Gestational diabetes usually starts in the middle or towards the end of pregnancy.
How common is gestational diabetes?
Gestational diabetes is very common. It may affect up to 18 in 100 women during pregnancy. You are more likely to develop gestational diabetes if you have any of the following risk factors:
- your body mass index (BMI) is 30 or higher
- you have previously given birth to a large baby, weighing 4.5kg or more
- you have had gestational diabetes before
- you have a parent, brother or sister with diabetes
- your family origin is South Asian, Chinese, African-Caribbean or Middle Eastern.
What is risk assessment of gestational diabetes?
Screening for GDM by maternal characteristics and obstetric history can predict about 55%, 70% and 85% of cases of GDM at respective false positive rates of 10%, 20% and 40%.
Predictors of GDM are previous history of GDM, family history of first or second degree relative with diabetes mellitus, maternal age, weight, height, racial origin, method of conception and birth weight of the neonate in the last pregnancy
To calculate your personal risk for GDM click here
How will I be checked for gestational diabetes?
If you have any of the above risk factors, you should be offered a glucose test during your pregnancy. This may be a simple blood test in early pregnancy and/or a glucose tolerance test (GTT) when you are between 24 and 28 weeks pregnant. A GTT involves fasting overnight (not eating or drinking anything apart from water):
In the morning, before breakfast, you will have a blood test. You are then given a glucose drink.
The blood test is repeated 1–2 hours later to see how your body reacts to the glucose drink.
What does gestational diabetes mean for me and my baby?
Most women who develop diabetes in pregnancy have healthy pregnancies and healthy babies but occasionally gestational diabetes can cause serious problems, especially if it goes unrecognized. Diagnosing and treating gestational diabetes reduces these risks. It is important to control the level of glucose in your blood during pregnancy. If your blood glucose is too high, your baby will produce more insulin, which can make your baby grow bigger and increases the likelihood of having your labor induced, caesarean section, serious birth problems and stillbirth. These risks are higher if gestational diabetes is not detected and controlled. A baby that is making extra insulin may have low blood glucose levels after birth and is more likely to need additional care in a neonatal unit. Your baby may also be at greater risk of developing obesity and/or diabetes in later life. Controlling your levels of blood glucose during pregnancy and labor reduces the risks of all these complications for you and your baby.
Healthy eating and exercise
The most important treatment for gestational diabetes is a healthy eating plan and exercise. Gestational diabetes usually improves with these changes although some women, despite their best efforts, need to take tablets and/or give themselves insulin injections. You should have an opportunity to talk to a dietician about choosing foods that will help to keep your blood glucose at a healthy and stable level.
Monitoring your blood glucose
After you have been diagnosed with gestational diabetes, you will be shown how to check your blood glucose levels and told what your ideal level should be. If it does not reach a satisfactory level after 1–2 weeks, or if an ultrasound scan shows that your baby is larger than expected, you may need to take tablets or give yourself insulin injections.
Monitoring your baby
You should be offered extra ultrasound scans to monitor your baby’s growth more closely.
Advice and information
During your pregnancy, consult physicians and midwives who will give you information about:
• Baby birth planning, including birth chart and types, pain relief (anesthesia), and changes in your treatment during and after the birth of your baby
• Care of the baby after birth
• Care for you and your baby including contraception.
Will I need treatment?
Up to one in five women with gestational diabetes will need to take tablets and/or have insulin injections to control their blood glucose during pregnancy. Your healthcare team will advise you what treatment is best for you.
If you do need insulin, your specialist diabetes nurse will explain exactly what you need to do. This will include showing you how to inject yourself with insulin, how often to do it and when you should check your blood glucose levels.
When is the best time for my baby to be born?
Ideally you should have your baby between at 38 and 40 weeks of pregnancy, depending on your individual circumstances.
How will I have my baby?
If your ultrasound scans have shown that your baby is large, your healthcare team should discuss the risks and benefits of vaginal birth, induced labour and caesarean section with you.
What happens in labor?
It is important that your blood glucose level is controlled during labor and birth and it should be monitored every hour during labor to ensure it stays at a satisfactory level. You may be advised to have an insulin drip to help control your blood glucose level. During labor, your baby’s heart rate should be continuously monitored.
What happens after my baby is born?
- Your baby will stay with you unless he or she needs extra care.
- Breastfeeding is best for babies, and there’s no reason why you shouldn’t breastfeed your baby if you have gestational diabetes. Whichever way you choose to feed your baby, you should start.