Oral Glucose Tolerance Test (OGTT) in Pregnancy

Oral Glucose Tolerance Test (OGTT) in Pregnancy.

We understand that having tests in pregnancy can be worrying, we hope the following information is helpful and reassures you.

Why am I having this test? 

You have been invited for this test because you may have risk factors for developing Gestational Diabetes (Diabetes in pregnancy). Sometimes this is abbreviated to GDM. 

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. If you are more than 36 weeks gestation, your midwife or obstetrician will discuss your options, if there are any signs that GDM is developing.   

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 happens when your body cannot produce enough insulin – a hormone that helps control blood sugar levels – to meet your extra needs in pregnancy. 

We invite anyone within one or more of the following groups, to have an OGTT:  

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 tummy plots above the 97^th 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.

Please talk to your midwife if you wish to discuss alternatives. However, management of GDM is more effective when detected early. 

How should I prepare? 

From midnight the night before the test you can drink water but you must not  

• eat or drink anything (except water)  
• chew gum  
• smoke 
• vape 
• apply nicotine patches  

You may only take any prescribed medications if required (if your medications need to be taken with food, or they are over the counter vitamins/supplements, delay the dose until after your OGTT test).

What will happen?  

The OGTT consists of 2 blood tests taken 2 hours apart. After the first blood sample is taken, you will be given a very sweet drink called Polycal®, which you need to drink within 5 minutes.

You will then be asked to sit in the waiting room for 2 hours, you may drink water to thirst, but we ask you to stay seated as much as possible, as moving around can affect the accuracy of the results. Then a further blood sample will be taken.  

After the second blood sample has been taken, the test is complete and you can go home. You are welcome to have something to eat and drink in the waiting room before you leave.  

During the test you must not eat, drink (except water), chew gum, smoke, vape or apply nicotine patches because these things can affect the accuracy of the results.  

We ask you to stay at the hospital and sit down for the two-hour wait, as physical activity can affect the accuracy of the results. 

If the above guidance is not adhered to, the test will be stopped, and we will rebook it for another day.

If you are feeling faint or unwell at any time during the test, please alert the staff. 

What should I bring with me? 

• Book/Magazine/device/phone or anything to pass the time whilst waiting. 
• Something to eat and drink after the test is complete. 
• There are cafés/shop on each hospital site, but it is a good idea to have something small to eat with you, in case you need to have something quickly.  

How will I get my results? 

The results of the test usually take 1-2 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. 

For more information about Gestational Diabetes, please look at: Gestational diabetes | Causes and symptoms | Diabetes UK 

Contact details

Please contact your local hospital or your community midwife if you have any questions or concerns or need to rearrange your appointment. 

• Worcester Day Assessment Unit: 01905 760594
• Kidderminster Maternity Hub:  01562 512376
• Redditch (Alexandra) Antenatal Clinic: 01527 512004
• Evesham: 01386 502323 (please leave a message).

Further information

If your symptoms or condition worsens, or if you are concerned about anything, please call your GP, 111, or 999. 

Patient Experience

We know that being admitted to hospital can be a difficult and unsettling time for you and your loved ones. If you have any questions or concerns, please do speak with a member of staff on the ward or in the relevant department who will do their best to answer your questions and reassure you.

Feedback

Feedback is really important and useful to us – it can tell us where we are working well and where improvements can be made.

There are lots of ways you can share your experience with us including completing our Friends and Family Test – cards are available and can be posted on all wards, departments and clinics at our hospitals. We value your comments and feedback and thank you for taking the time to share this with us.

Patient Advice and Liaison Service (PALS)

If you have any concerns or questions about your care, we advise you to talk with the nurse in charge or the department manager in the first instance as they are best placed to answer any questions or resolve concerns quickly.

If the relevant member of staff is unable to help resolve your concern, you can contact the PALS Team. We offer informal help, advice or support about any aspect of hospital services & experiences.

Our PALS team will liaise with the various departments in our hospitals on your behalf, if you feel unable to do so, to resolve your problems and where appropriate refer to outside help.

If you are still unhappy you can contact the Complaints Department, who can investigate your concerns. You can make a complaint orally, electronically or in writing and we can advise and guide you through the complaints procedure.

How to contact PALS

Telephone Patient Services: 0300 123 1732 or via email at: wah-tr.PALS@nhs.net

Opening times

The PALS telephone lines are open Monday to Friday from 8.30am to 4pm. Please be aware that you may need to leave a voicemail message, but we aim to return your call within one working day.

If you are unable to understand this leaflet, please communicate with a member of staff.

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