Glucose Tolerance Test - GTT
Location: ----------------------
Date & Time: ----------------------
Why am I having this test?
You have been invited to have this test because you may have risk factors for developing Gestational Diabetes (Diabetes in pregnancy). Sometimes this is abbreviated to GDM. Gestational diabetes is high blood sugar that develops during pregnancy and usually disappears after giving birth. It can happen at any stage of pregnancy but is more common in the second or third trimester. It is a condition in which a hormone made by the placenta prevents the body from using insulin effectively. Glucose builds up in the blood instead of being absorbed by the cells.
Gestational Diabetes can cause problems for you and your baby, during pregnancy and after birth. The risks can be reduced if the condition is detected and well managed. You may be offered this test at any stage during your pregnancy, up to 36 weeks.
We invite anyone within one or more of the following risks to have an OGTT:
- BMI above 30 kg/m2
- Previous macrosomic baby weighing more than 4.5 kg or more than 95th birthweight centile
- First-degree relative with diabetes i.e. sibling or parent
- Family origin with a high prevalence of diabetes: South Asian (e.g. India, Pakistan, Bangladesh, Thailand, Philippines), Caribbean, African or Middle East (e.g. Saudi Arabia, UAE, Iraq, Jordan, Syria, Oman, Qatar, Kuwait, Lebanon, Egypt).
- Polycystic Ovarian Syndrome at Booking
- Previous IUD
- Maternal age over 40 (at booking)
- IVF pregnancy
- Multiple pregnancy
- Taking the following anti-psychotic drugs: Clozapine, Olanzapine, Quetiapine or Risperidone
You may not have any of the above risk factors, but something may have been found during your pregnancy which might suggest Gestational Diabetes is developing, such as:
- Glucose detected on a urine dip test (either more than once or higher levels on one occasion)
- Polyhydramnios (excess fluid around the baby confirmed on ultrasound scan)
- Ultrasound scan showing the measurement of your baby’s estimated weight or your baby’s tummy plots above the 97th growth centile
- Ultrasound scan measurement showing the estimated weight of your baby is increasing rapidly
It may be suggested that you have this test repeated at different times during pregnancy if new risk factors develop. You can choose to decline this test or stop the test at any time. However, management of GDM is more effective when detected early.
Are there any risks or side effects?
Most people do not experience any side effects. Some people find it hard to drink all the drink due to the sweet, sugary flavour and because of the amount of drink. Drinking quickly may make you feel nauseous, but this usually passes quickly. You may feel faint or dizzy before, during or after the test. This is almost always because you have not eaten. If you are feeling faint or unwell at any time during the test, please alert the staff.
How should I prepare for the test?
From midnight the night before the test you can drink water, but you must not:
- eat or drink anything (except water)
- chew gum
- smoke or vape
- apply nicotine patches
What will happen during the test?
- A member of staff will check your personal details and answer any questions you have.
- A sample of blood will be taken from your arm by a trained member of staff.
- You will then be given a glucose drink. It is important that you drink this within 5 minutes of starting.
- You will be asked to take a seat back in the waiting area and stay there for 2 hours. During this time, you should remain seated as much as possible. You may drink sips of plain water, but you must not eat or smoke, chew gum, smoke, vape or apply nicotine patches because these things can affect the accuracy of the results.
- After 2 hours a second blood sample will be taken from your arm. This completes the test, and you will be able to go.
For the test to be accurate it is important that:
- The glucose drink is taken properly
- The blood samples are taken at the right times
- You do not eat before and during the test
- You rest during the test
After the test
When the test is complete, you can go home. You are welcome to have something to eat and drink in the waiting room before you leave.
If the test guidance is not adhered to, the test will be stopped, and we will rebook it for another day.
Test Results
The results of the test usually take 1-3 days to come back to us. If you do not hear anything from us, your results are within the normal range and no further action is required at this time. If your results are raised, this indicates that you have got Gestational Diabetes. Someone will call you within 2-3 days to discuss this, make the recommended appointments going forward and answer any of your questions. Please make sure your telephone number is up to date on your Badger notes app.
What if I don’t want to have the test?
It is your choice to decline the glucose tolerance test but please make sure you are aware of the risks of undiagnosed gestational diabetes. Please let your community midwife know if you do not want to have the test.
If you have Gestational Diabetes that is not treated, you are at increased risk of the complications below:
- Premature birth
- Large baby
- Stillbirth
- Increased risk of forceps/caesarean section
- Increased risk of a shoulder dystocia
- Neonatal hypoglycaemia (your baby having low blood sugar in the early days of life)
What can you do if you are concerned about the OGTT?
If you have any further questions or require any further information, please contact your community midwife or Day Assessment Unit on 01228 814506. If you are receiving care at CIC, or the community midwife team for Copeland on 01946523229 or 01900705033 for Allerdale if you are receiving care at WCH.
Where to get help:
Your Diabetes team contact -
Name:…………………………................................................
Your Midwifery Team contact-
Name:………………………………………………………........
Local hospital contact no.-
Name:……………………….....................................................
What are the test results and what do they mean?
During Pregnancy
The level of glucose in your blood before and after the glucose drink will show whether you have ‘gestational diabetes’ (diabetes in pregnancy) or not.
Any high glucose level in a GTT during pregnancy is called gestational diabetes
After your pregnancy
The GTT will be repeated and the exact condition you have will be determined from the table below.
Confidentiality
‘The Trust’s vision is to keep your information safe in our hands.’ We promise to use your information fairly and legally, and in-line with local and national policies. You have a right to understand how your information is used and you can request a copy of the information we hold about you at any time.
For further information on confidentiality contact the Information Governance Team:
Information.Governance@ncic.nhs.uk | 01228 603961
Feedback
We appreciate and encourage feedback, which helps us to improve our services. If you have any comments, compliments or concerns to make about your care, please contact the Patient, Advice & Liaison Service:
pals@ncic.nhs.uk | 01228 814008 or 01946 523818
If you would like to raise a complaint regarding your care, please contact the Complaints Department:
complaints@ncic.nhs.uk | 01228 936302