5 tips for preparing for your gestational diabetes test

Rebecca McPhee
Dietitian Member of the DAA

3 Minutes

With all the ultrasounds, blood tests and check-up, you're probably feeling like the doctor's surgery is currently your second home! Although it is comforting to know that you and your baby are getting lots of attention to ensure your pregnancy journey is a safe one, part of this journey includes testing for gestational diabetes.  

The test for gestational diabetes usually occurs in the 24th to 28th week of your pregnancy and takes place over a few hours, so here are five useful tips for preparing for your diabetes test.  


What is gestational diabetes?  


Gestational diabetes occurs during pregnancy when the hormones produced by the placenta block the action of a women's insulin in regulating blood sugar levels. Irregular blood sugar levels can lead to some complications including early labour, bigger babies and high blood pressure for mums - among others.  

Gestational diabetes usually goes away when the baby is born; however, research shows that women who have had gestational diabetes are 50% more likely to develop type 2 diabetes later in life. Further, if you have Gestational diabetes in your first pregnancy, you have a 30-69% chance of it recurring in future pregnancies. 

The good news is that in most cases, gestational diabetes can be managed to ensure a healthy mum and bub. 


How is gestational diabetes tested?  


Diagnosis of gestational diabetes typically involves a series of blood tests which take place over several hours and includes an oral glucose tolerance test (OGTT). This test is conducted between 24 and 28 weeks; however, your doctor may ask you to do this test earlier in your pregnancy if you have been presenting symptoms or risk factors for gestational diabetes. 


Five useful tips to prepare you for the test:  


1. Skip your morning toast and latte  

This test is conducted in a fasted state, which means not eating for 8 – 10 hours. The most practical thing to do is to fast overnight and skip breakfast so that you can be tested in the morning.  


2. Bring your favourite book  

There will be a wait in between the two tests, so be sure to make the most of this downtime by bringing a good book! Firstly, blood will be taken to check your fasting blood sugar level. Following this, you will be given a sweet, sugary drink (containing glucose). Your blood will then be tested one and two hours later. During this wait time, you will be asked to refrain from eating or drinking anything except water.  


3. Don't be concerned about drinking a glucose drink

So, the sweet drink doesn't taste the best, but it will not cause gestational diabetes or harm you or your baby. The test is observing how well your body processed the glucose over the period when you were sitting in the pathology lab.  


4. Know when to expect the results 

Your test results are usually ready within 48 hours and will be sent to your GP/obstetrician. In some cases, they can be available later the same day.     

A diagnosis of GDM is made if one or more of the following glucose levels is elevated;   

· Fasting glucose ≥ 5.1mmol/L   

· 1‐hr glucose ≥ 10.0mmol/L  

· 2‐hr glucose ≥ 8.5mmol/L       

Source: Australian Diabetes in Pregnancy Society (ADIPS) criteria for the diagnosis of gestational diabetes 


5. The test result is not all doom and gloom  


Testing for gestational diabetes needn't be worrisome. Think of it as a positive step towards reducing complications and having a safe, healthy pregnancy. And, you are diagnosed with gestational diabetes; there are various treatment options available that can include a combination of lifestyle modification, oral medication and insulin injections if needed.  



  • You will need to fast for 8 – 10 hours, so fasting overnight makes the gestational diabetes test easier. 

  • The test takes place over several hours so bring a good book or magazine to help the time pass.  

  • Don't be concerned about the oral glucose test as it is safe for you and your baby.  

  • Your results are usually available within 48 hours.  

  • If you do receive a diagnosis of gestational diabetes, there are various treatment options available.  


Undertaking the gestational diabetes test is a pro-active step towards a healthy pregnancy and is well worth the time invested in understanding whether you are at risk.   

For more information about gestational diabetes including recipes, tips, hacks, events and so much more, join the Capital Chicks CANberra online community today.  


  • O’Sullivan J. Diabetes Mellitus after GDM.  Diabetes 1991; 29 (Suppl.2): 131‐35 
  • Moses RG. The recurrence rate of gestational diabetes mellitus in subsequent  pregnancies. Diabetes Care 1996; 19: 1348‐1350
  • Stephanie MacNeill et al. Rates and Risk Factors for Recurrence of Gestational Diabetes. Diabetes Care 2001 Apr; 24(4): 659-662
  • Nankervis A, McIntyre HD, Moses R, Ross GP, Callaway L, Porter C, Jeffries W,  Boorman C, De Vries B, McElduff. ADIPS Consensus Guidelines for the Testing and  Diagnosis of Gestational Diabetes Mellitus in Australia . Australasian Diabetes in Pregnancy  Society


  • www.diabetesnsw.com.au
  • www.ndss.com.au/wp-content/uploads/resources/booklet-gestational-diabetes-caring-for-yourself-and-baby.pdf
  • www.diabetesaustralia.com.au 
  • www.adips.org

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