Gestational Diabetes (also known as Gestational Diabetes Mellitus) is a type of diabetes that some women get when they are pregnant. According to Diabetes Australia "between 3% to 8% of pregnant women will develop gestational diabetes around the 24th to 28th week of pregnancy, however, some may be earlier".
SCREENING FOR GESTATIONAL DIABETES
The recommended screening test for GDM is performed at 26-28 weeks' gestation (according to RANZCOG Management Guidelines)
SHOULD I TAKE THE TEST?
Clients often ask me whether they think they should do the test... and the answer is that is entirely up to you. However, you may want to consider it if you meet one of the risk factors that have been identified. These include:
- Previous GDM
- Previously elevated blood glucose level
- Ethnicity: south and southeast Asian, Aboriginal, Pacific Islander, Maori, Middle Eastern, non-Caucasian African
- Age ≥40 years
- Family history of diabetes mellitus (first degree relative with diabetes mellitus or a sister with GDM)
- Obesity, especially BMI >35 kg/m2
- Previous macrosomia (baby with birth weight >4 500 g or >90th percentile)
- Polycystic ovarian syndrome
- Medications: corticosteroids, antipsychotics
WHAT HAPPENS IF I HAVE GD AND I DON'T TAKE THE TEST?
According to the RANZCOG Guidelines:
Although there is no evidence that perinatal mortality is increased in pregnancies with treated GDM, some studies have shown perinatal mortality to be increased in untreated GDM.
GDM is associated with increased perinatal morbidity, the characteristics of which are the same as for infants of mothers with overt diabetes (eg, macrosomia, neonatal hypoglycaemia, hyperbilirubinaemia, respiratory distress syndrome).
Reference: Hod M, Merlob P, Friedman S, et al. Gestational diabetes mellitus: a survey of perinatal complications in the 1980s. Diabetes 1991; 40 (Suppl 2): 74-78.
WHY ARE THERE MORE WOMEN GETTING GD LATELY?
One problem that I hear a lot about lately, is mentioned here in August 2013 Australian Family Physician website: http://www.familypracticenews.com/single-view/ultrasound-diagnosis-of-fetal-macrosomia-found-inaccurate/36fa34152d.html
- that is there are currently two sets of diagnostic criteria in use for diagnosing GD. The revised guidelines will increase the number of pregnant women diagnosed with GD by a staggering 50%! This translates to the prevalence of GDM being likely to increase to around 12–14% with the new diagnostic criteria.
PREVENTING A GD DIAGNOSIS
If you are looking to prevent a GD diagnosis you might want to check out Gloria Lemay's article 'Helping your client avoid a Gestational Diabetes diagnosis': http://wisewomanwayofbirth.com/helping-your-client-avoid-a-gestational-diabetes-diagnosis/
WHAT ARE THE RECOMMENDATIONS FOR DELIVERY WHEN YOU HAVE GD?
Whilst the RANZCOG Guidelines for Timing of Delivery state:
- Delivery before full term is not indicated unless there is evidence of macrosomia, polyhydramnios, poor metabolic control or other obstetric indications (eg, pre-eclampsia or intrauterine growth retardation).
My experience has been that the few women that I have met who have been diagnosed with GD and been treated for it, were then subject to increased pressure to undergo induction and/or where told things that led them to believe that their bodies were not capable of birthing their babies (due to them being too large) and that a caesarian birth would be necessary.
If you are interested to know how an ultrasound diagnosis of big baby can be wrong - the following article may be of interest: http://www.familypracticenews.com/single-view/ultrasound-diagnosis-of-fetal-macrosomia-found-inaccurate/36fa34152d.html
For more about 'big babies' more here on Evidence Based Birth: http://evidencebasedbirth.com/does-gestational-diabetes-always-mean-a-big-baby-and-induction/
With the increased number of women being diagnosed with GD you can see the flow on effect - that an increasing number of women are being subject to a cascade of interventions, and increasingly ending up with caesarian section births.
Don't get me wrong some times c-section birth is very necessary and life saving - but for the Mum for subsequently finds out that she was bamboozled into an elective c-s that was unnecessary the impact on her mental health can be devastating. With psychiatric illness is the leading cause of maternal death in Australia - the inference is clear - we need to do everything we can to ensure that women in labour are making truly informed choices based on accurate information.
So for those women who are wanting to know whether to take the test - in the end the choice is up to you. You need to be aware of both the risks and the consequences of a positive diagnosis. You also need to be prepared that you may have a fight on your hands to achieve a natural hospital birth without fear.
For more information on GD screening, our local Community Midwifery Program has a fact sheet titled: Screening for Gestational Diabetes (http://www.cmwa.net.au/_literature_88952/CMP_Info_Sheet_-_Screening_for_Gestational_Diabetes) that provides a succinct summary of information that may help you decide. In the end it your body, your baby and your choice.
IF YOU ALREADY HAVE GESTATIONAL DIABETES
If you have already been diagnosed with GD the following articles may help:
and finally you need to read this: Birth without fear: The truth about gestational diabetes and why it's not your fault