UAlberta medical research informs U.S. guidelines for gestational diabetes

Raquel Maurier - 12 July 2013

Medical researchers at the University of Alberta are providing their expertise to the U.S. government to help guide recommendations on gestational diabetes screening.

Faculty of Medicine & Dentistry researcher Lisa Hartling recently published her team's work comparing different approaches to screening for gestational diabetes and the impact of treatment. The findings were presented to the U.S. National Institutes of Health and the U.S. Preventive Services Task Force, which would like to see standardized screening and diagnosis of gestational diabetes across the United States. The findings were also published in the peer-reviewed journal, Annals of Internal Medicine, earlier this year.

The research was funded by the U.S. government via the Agency for Healthcare Research and Quality to provide evidence for recommendations about how to best screen for and diagnose gestational diabetes. The agencies involved also wanted to identify the harms and benefits of treating women for gestational diabetes. There are 11 centres in North America that do this type of evidence based research for the Agency for Healthcare Research and Quality - Hartling's team is the only such group in Canada and was chosen because of their expertise and knowledge in this area.

Hartling's team reported on the variations in screening recommendations by different organizations around the world. For example, some recommend that pregnant women undergo two tests. If the first test registers high levels of glucose, then patients go for a second, more definitive test. Other organizations recommend pregnant women receive only one test. Some organizations screen all pregnant women for gestational diabetes, while others only screen women who exhibit risk factors.

The team found that a fasting blood test was very effective at ruling women out for gestational diabetes. Whereas another test where women drink a sugary drink before a blood test was better at pinpointing women who had gestational diabetes. This sugary drink test resulted in fewer false positives, although many still occur.

"In medical research you ideally want to find the tests that are most effective at both pinpointing those who have a condition, and identifying those who don't have the condition," Hartling explains.

"There is no gold standard test for this condition, which is why so many organizations have come up with different approaches on how to test for gestational diabetes. The National Institutes of Health would like to see some of these controversies resolved. They aim to develop a consensus statement to guide practice in the United States."

The potential downsides identified to treating women for gestational diabetes - through glucose monitoring, modified diets, and insulin if needed - were increased costs and the possibility of more apprehension over the 'label' of gestational diabetes. For example, some studies found that care for women with gestational diabetes may be more precautionary - such as inducing labour and admitting babies to neonatal intensive care.

Hartling and her team also examined whether mothers and their babies experienced health improvements when gestational diabetes was treated. They found that the benefits were many - fewer delivery problems, more healthy sized babies and less high blood pressure for mothers.

Hartling's team members included colleagues from the Department of Pediatrics, and a fellow researcher from the University of Calgary.