COVID-19 and Gestational Diabetes Screening, Diagnosis and Management

06 April 2020

Updated on 20 August 2020

RANZCOG accepts that diagnostic criteria for gestational diabetes mellitus (GDM) are controversial and that there is no universal agreement. During the Covid-19 pandemic, we must balance the competing demands of the benefits of diagnosis and management of gestational diabetes with the need to reduce the risk of exposure associated with testing and ongoing care. The majority of women with gestational diabetes are managed with advice regarding dietary modification and exercise, and this advice should continue to be given to all women in pregnancy.
Guidance for practitioners and patients during the Covid-19 pandemic will necessarily change according to jurisdictional advice and social-distancing restrictions, rates of community transmission and availability of resources. Due to the low rates of community transmission and the current successful flattening of the curve in Australia and New Zealand, RANZCOG recommends: 
If a woman is currently positive for COVID-19, symptomatic or in isolation awaiting test results, any GDM testing should be delayed until after that period.
For patients where pathology services can meet social distancing requirements:
Perform a 2 hour OGTT
  • In the first trimester for women with identifiable risk factors
  • For all women at 24-28 weeks gestation
For patients where pathology services are unable to meet social distancing requirements, the following advice should apply
  • For patients with identifiable risk factors for GDM in early pregnancy, an HbA1c should be performed with antenatal serology. A cutoff of 5.9% should be considered diagnostic of GDM
  • Women with previous GDM could be considered as having GDM and commence home blood glucose monitoring from 28 weeks gestation. Alternatively they can undergo screening as below
  • All other women should have a fasting blood glucose at 24-28 weeks
    • Glucose is >=5.1mmol/L: assumed GDM.
    • Glucose <4.7 mmol/L.: no GDM
    •  Glucose 4.7-5.0: a 2-hour OGTT should be performed to confirm GDM status
  • In women diagnosed with GDM, usual blood glucose monitoring protocols, insulin, dietary and exercise advice should be followed
  • Women with gestational diabetes should have an ultrasound at 36 weeks if there is clinical suspicion of macrosomia, or the presence of other co-morbidities which may cause fetal growth restriction
  • Timing of delivery will need to consider other maternal risk factors for perinatal morbidity
  • Postnatal GTT should be deferred until 6 weeks, if distancing can take place, or delay until this is possible, unless post-natal blood glucose levels are elevated
This advice is not exhaustive and does not attempt to cover every scenario. Furthermore, individual clinical circumstances vary and all clinicians should apply appropriate discretion.



Dr Pieter Mourik (AM)

Being recognised in the Australia Day honours was a highlight for this rural medicine advocate.



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