Gestational Diabetes: To Test Or Not To Test

by Birth Without Fear on June 21, 2013

If you’ve been pregnant, chances are you’ve had to decide whether or not to take a ‘Gestational Diabetes’ test. You’ll usually be given a form to go have one of two ‘routine’ tests, the Glucose Challenge Test or the Glucose Tolerance Test, and that’s that. When I was pregnant I wasn’t really given any explanation about the test except that I would have a drink that was “like sweet , flat lemonade” (which it kind of is). I had no idea what Gestational Diabetes was. I didn’t think I had the option not to take the test, and I had no idea what ‘failing’ the test would mean. Unfortunately, it was only after I had ‘failed’ the test and was diagnosed with Gestational Diabetes that I researched more about the unreliability of the formal tests and the impact the diagnosis would have on my prenatal care.

The Glucose Challenge Test (GCT) is a relatively simple test: at 24-28 weeks gestation you drink a sweet drink with a high glucose load, usually around 50g of carbohydrate, and a blood sample is taken one hour later. Your blood glucose or blood sugar levels are tested and then compared to the ‘average’ levels. If your blood sugar levels are over the ‘average’, you are considered ‘at risk’ of Gestational Diabetes Mellitus (GDM), and will be sent for the Glucose Tolerance Test (GTT). This is a more involved test. You may be sent straight to this test if you are considered high risk of developing GDM. You must fast for approximately 10 hours, and then attend the pathology clinic for around 2 ½ hours. You will need to drink another sweet glucose drink – this one usually has around 75g of carbohydrate (the equivalent to eating 5 tablespoons of sugar or 3-4 pieces of white bread). A series of three blood tests will be taken – one before you have the glucose drink, another test one hour after you’ve had the drink, and another one hour after that. This series of blood tests are graphed and compared to the average levels. What the doctors are looking for is a normal fasting blood sugar level, a blood sugar peak at one hour, and then back within ‘normal’ range two hours after the drink.

gestational diabetes blood glucose meter

The ‘average’ and ‘cut-off’ levels seem to vary depending on where you live, however generally in the USA, UK, Australia  and New Zealand, women who have blood sugar levels above 8-9mmol/L (140-160 mg/dl) at two hours after drinking the 75g-glucose drink get the diagnosis of GDM.

Recommendations from some of the prominent College’s of Obstetrics and Gynaecology (ACOG, RAZNCOG and RCOG), state that every pregnant woman, regardless of risk or medical history, should be screened because the rate of GDM among expectant mothers is rising – although, that statement itself is ironic! They also claim that the GCT/GTT is essential: the potential ‘risks’ of GDM mean that women need to be under strict management during pregnant, labour and birth for optimal maternal and fetal outcomes. However, there are many medical and birth professionals who, after reviewing the data themselves, have decided to do away with routine testing for GDM.

When you think about the test, it’s not surprising that many women ‘fail’ or are considered ‘borderline’ or ‘pre-diabetes’. Most women are also asked to sit and not engage in any sort of activity for the entire two hour test, which is a factor that can lead to higher blood glucose levels. Pregnant women also naturally have some form of insulin resistance thanks to the pregnancy hormones. You drink the sweet glucose drink (a fast-release carbohydrate load that is larger than someone would have in an average meal) without any form of protein to slow the release of glucose. It’s easy to see why many have decided that the formal tests are not an accurate representation of the mothers ability to tolerate carbohydrates in everyday meals. Dr. Sarah Buckley, GP and obstetric professional, recommends against routine testing for GDM for most women. Ina May Gaskin, a Certified Professional Midwife and founder of The Farm Midwifery Center, also reports that up to seventy percent of women who repeat the test get a different result than on their initial test.

But… what are the options?

Well, a lot doctors and midwives won’t give you any. At a hospital appointment I once had, my partner and I sat and listened to a midwife argue for 15 minutes with a woman who refused the routine GDM test. Over the course of the conversation, the woman asserted herself, telling them she was 34 weeks pregnant, she checked her blood sugar at home periodically, she’d had a scan, everything was fine, and she didn’t want the test. The midwife belittled her, bringing her weight into the conversation. Tried to scare her by predicting the size of the baby. Insinuate that she was uneducated and naive and she didn’t understand the risks. She even tried to pull the “you’re jeopardising the safety of your baby, it’ll be on your head if something happens” card. I’m not sure what became of the woman, but she was just one woman in what I imagine is a sea of pregnant women trying to assert themselves in this medicalised and interventionist culture of birth at the moment.

gestational diabetes glucose meter and strips

The mother in my story knew a great option. One that WAS reflective of real life – periodic home blood sugar tests. If you are comfortable with refusing the GCT/GTT, but still feel the need to have some kind monitoring, then this is one of your options. It is logical and obvious that testing two hours at home after eating your lunch and doing whatever you normally do afterwards, would give you a good idea about whether or not your body is having trouble. These results are usually compared to the ‘average’ results – usually aiming for less than 5.5mmol/L (100mg/dl) while fasting, and less than 6.7mmol/L (120mg/dl) two hours after meals. This could give you an idea of whether you need to readjust your diet or consider medical management.  And, going by the stories I have read and the women I have talked to, this seems to be the option many homebirth midwives give their clients. However, it can be a hassle if you forget, or if you’re in the habit of frequent eating, because for accurate results you need to eat your meal and then nothing but water for two hours. This is because other food or drink could raise your blood sugar levels and give an inaccurate reading of your body’s ability to handle the carbohydrate load of your meal.

Another option some professionals give is to keep the formal test, but swap the drink for something else with an equivalent carbohydrate load. This attempts to mimic a real-life situation, and is thought to be more accurate than a test based on the glucose in the sweet drink. However, this is not recommended by some medical professionals because eating a meal takes more time than the 5-10 minute limit you are given when drinking the glucose drink. Also, different types of foods have slower or faster releasing glucose, so the results can’t really be compared to the ‘average’ results after the glucose drink.

If you choose to forgo the routine testing for less invasive tests or none at all, educating yourself is important. Be aware of the quality of your carbohydrates and how to eat well-balanced meals that include low-GI (glycaemic index) carbohydrates. This is a good way to keep your body healthy, diabetes or not. Dr Michael Odent explains this practice quite well in his article ‘Gestational Diabetes: A Diagnosis Still Looking For a Disease?’ (linked below). Alongside a balanced diet, Buckley, Gaskin and Odent all recommend regular low impact exercise throughout pregnancy to help the body lower blood glucose levels naturally.

Keep reading: The Truth About Gestational Diabetes {And Why It’s Not Your Fault}

 

References:

American College of Obstetricians and Gynaecology, The [ACOG]. (2011). Screening and diagnosis of gestational diabetes mellitus. Committee Opinion No. 504. 751–3. Retrieved on March 31, 2013, from http://www.acog.org/Resources_And_Publications/Committee_Opinions/Committee_on_Obstetric_Practice/Screening_and_Diagnosis_of_Gestational_Diabetes_Mellitus

Australasian Diabetes in Pregnancy Society, The [ADPS]. (2002). Gestational Diabetes Mellitus – management guidelines. Retrieved on March 31, 2013, from http://www.ranzcog.edu.au/the-ranzcog/policies-and-guidelines/policies-procedures-document-library/doc_download/454-gestational-diabetes-mellitus-management-guidelines.html

Buckley, S. J. (2008). ‘Gestational Diabetes Testing’. In Gentle Birth, Gentle Mothering: A Doctor’s Guide to Natural Childbirth and Gentle Early Parenting Choices. Retrieved on March 31, 2013, from http://www.fullcirclemidwifery.com/2009/02/gestational-diabetes-information/

Goer, H. (1996). Gestational Diabetes: The Emperor Has No Clothes. The Birth Gazette, 12(2). Retrieved on April 1, 2013, from http://www.gentlebirth.org/archives/gdhgoer.html

Gaskin, I. M. (2003). Ina May’s Guide to Childbirth. United States: Bantam.

National Institute for Health and Clinical Excellence [NICE]. (2008). Diabetes in pregnancy: Management of diabetes and its complications from pre-conception to the postnatal period. Clinical Guideline 63. Retrieved on April 1, 2013, from http://www.nice.org.uk/nicemedia/pdf/CG063Guidance.pdf

Odent, M. (2004). Gestational Diabetes: A Diagnosis Still Looking For a Disease? Primal Health Research: A New Era in Health Research, 12(1). Retrieved on April 1, 2013, from http://www.bellybeginnings.com/Handouts/GestationalDiabetes-Odent.pdf

Royal Australian and New Zealand College of Obstetricians and Gynaecologists, The [RANZCOG]. (2011). Diagnosis of Gestational Diabetes Mellitus. Retrieved on March 31, 2013, from http://www.ranzcog.edu.au/component/docman/doc_download/941-c-obs-07-diagnosis-of-gestational-diabetes-mellitus-.html

Royal College of Obstetricians and Gynaecologists, The [RCOG]. (2011.) Diagnosis and Treatment of Gestational Diabetes. Scientific Impact Paper 23. Retrieved April 1, 2013, from http://www.rcog.org.uk/files/rcog-corp/uploaded-files/SIP_No_23.pdf

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