Knowledge Synthesis: Gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes; however, widening of the diagnostic criteria in Australia (and other countries) have led to an increase in incidence raising concerns about overdiagnosis of this condition. The overdiagnosis of Gestational Diabetes Mellitus (GDM) and its management is part of an active international debate. 

Doust (2022, MJA Perspective) discusses these issues in the context of a 2021 pragmatic randomised trial of GDM screening in the United States that found while the number of pregnant women diagnosed with GDM increased, no health benefits were seen for either mother or baby, highlighting the need for a review of the current Australian Guidelines.   

Overdiagnosis raises the possibility of potential harms for women, including life disruptions for the women diagnosed, psychological burdens, risk of more invasive forms of delivery, potential harms to the infant from restricted diets and the use of insulin, as well as increased costs and poor targeting of resources.  

Bandyopdhyay (2021) explored the impact of a GDM diagnosis on South Asian women in a qualitative study interviewing pregnant women diagnosed with GDM and health professionals providing care.  On the whole, both women and health care providers were dissatisfied with the care provided.  Women reported feeling loss of control over their pregnancy, and that the information provided on lifestyle modification (diet and exercise) for self-management was culturally and socially inappropriate and irrelevant to their needs. 

Diagnostic criteria for GDM were further complicated during the COVID pandemic as some States/Territories and health centres in Australia changed their guidelines or approach to testing to minimise the contact time pregnant women with others (Meloncelli 2021).  

The Conversation 
1 in 6 women are diagnosed with gestational diabetes. But this diagnosis may not benefit them or their babies

1. Bandyopadhyay M. Gestational diabetes mellitus: a qualitative study of lived experiences of South Asian immigrant women and perspectives of their health care providers in Melbourne, Australia. BMC Pregnancy Childbirth. 2021;21(1):500. 
2. Doust JA, Glasziou PP, d’Emden MC. A large trial of screening for gestational diabetes mellitus in the United States highlights the need to revisit the Australian diagnostic criteria. Med J Aust. 2022;216(3):113-5. 
3. Meloncelli N, Shipton E, Doust J, D’Emden M, McIntyre HD, Callaway L, et al. Clinicians’ perspectives on gestational diabetes screening during the global COVID-19 pandemic in Australia. Aust N Z J Obstet Gynaecol. 2022. 
4. Sharon Croxford, Deevya Gupta, Mridula Bandyopadhyay & Catherine Itsiopoulos (2021) An evaluation of dietary intakes of a selected group of South Asian migrant women with gestational diabetes mellitus, Ethnicity & Health, 26:4, 487-503, DOI: 10.1080/13557858.2018.1539217