Doctors in Australia believe that an urgent review of the diagnostic criteria for gestational diabetes should be undertaken following a large U.S. trial in 2021 that showed it might not be beneficial to the mother and baby.
The one-step approach to screening gestational diabetes mellitus (GDM), as determined by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG), was recommended over the Carpenter-Coustan two-step approach from the Australasian Diabetes in Pregnancy Society. Screening for gestational diabetes is necessary since it could lead to several long-term health issues, including cardiovascular disease in the mothers.
But in a report published in the Medical Journal of Australia, members of the Royal Australian College of General Practitioners (RACGP), alongside the U.S. National Institutes of Health (NIH) panel, expressed objection to the one-step approach as it didn't seem to benefit the mother and baby from increased monitoring. According to the panelist, there is no substantial evidence proving that women who have been diagnosed with gestational diabetes using the one-step approach but were otherwise normal in the two-step approach diagnosis needed more interventions.
Gestational Diabetes Overdiagnosis
Professor Jenny Doust of the University of Queensland's Clinical Epidemiology department said that the findings from the RACGP and the NIH's report validated their concerns about the one-step approach. She pointed out that while the number of women with gestational diabetes doubled using this process, it brought no significant health benefits.
The expert also said that if this became the universal standard, it would likely bring about "artificial results."
"If the new GDM criteria include women with milder disease in the disease definition, these women will add to the number of women diagnosed," Doust explained in a press statement. "But not to the number of women or infants with adverse outcomes, making it appear artificially as if results have improved."
The expert also highlighted that the result of the U.S. trial has been consistent with other Australian studies that showed the one-step approach could be disruptive, bringing more psychosocial burdens on the mother, who could risk her life and her baby's life with a more invasive delivery. The doctor also said that this process is more costly, especially for low-income families who do not have the resources to undergo various medical interventions.
One-Step vs Two-Step Approaches for GDM Screening
IADPSG's one-step approach requires pregnant moms to undergo a 75-g oral glucose tolerance test (OGTT) at 24 to 28 weeks. They are required to fast and take the tests after one hour and two hours. It only takes one abnormal result to classify the mom as a diabetic, which has attracted a lot of criticisms of overdiagnosis or misdiagnosis.
The Carpenter-Coustan two-step approach, on the other hand, requires a three-hour 100-g OGTT that has to show at least two abnormal results out of three to be considered as gestational diabetes. Experts worldwide have long debated which approach is better as no standardized test has been adopted globally.
Meanwhile, experts in the field of obstetrics and gynecology said that a gestational diabetes diagnosis needs to be followed through for life and not consider this as a "diabetes of pregnancy." Women with this condition risk developing type 2 diabetes and other severe diseases in the future. Thus, focusing on sugar control in the mother's diet should not be short-term only.
According to OBGYN Dr. Tamika Cross via Healthline, even if the mom has her sugar well-controlled while pregnant, she will have to undergo regular, long-term, and lifelong monitoring of her sugar intake to keep diabetes at bay.
