Newly Validated Algorithms Reveal Significant Increase in Rates of Diabetes in Pregnancy

A pair of recent publications in the Canadian Journal of Diabetes examined diabetes in pregnancy in Alberta. This research was conducted by CVC post-doctoral fellow, Dr. Deliwe Ngwezi, and was supervised by Drs. Padma Kaul and Anamaria Savu; other members of the team included Dr. Rose Yeung (University of Alberta) and Dr. Sonia Butalia (University of Calgary). 

The purpose of the first study was to validate the accuracy of alternative algorithms in identifying pre-existing type 1 or 2 diabetes (T1DM or T2DM) and gestational diabetes mellitus (GDM) in pregnant women. The study utilized data from a clinical registry of pregnant women who attended a diabetes clinic in Edmonton, Alberta between 2002 and 2009. The researchers assessed 3 alternative algorithms for identifying women with T1DM, T2DM, and GDM based on International Classification of Disease 10th Revision (ICD-10) codes, a universally recognized system for recording diagnoses in healthcare administrative data. The researchers found that the algorithm combining delivery hospital and outpatient clinic records during pregnancy performed the best for the detection of T1DM, T2DM, and GDM. 

In a second companion study, the researchers employed this new algorithm to determine temporal trends in the rates of T1DM, T2DM, and GDM in pregnancy over a 10 year period in Alberta, Canada. The study examined diabetes rates by residence (urban/rural), ethnicity, maternal age, and material deprivation (a measure of socio-economic status). 

While rates of T1DM remained constant, the researchers found that rates of GDM and T2DM in pregnancy more than doubled from 2005 to 2018, with higher rates observed in women of Chinese and South Asian ethnicity and women living in urban or materially deprived areas. Additionally, their findings indicated that rates of adverse maternal and neonatal outcomes were significantly higher in women with T1DM compared to those with T2DM and GDM. 

“Diabetes in pregnancy may impact the future health of both the mother and the child,” says Dr. Pama Kaul. “The increasing rates of pre-existing type 2 diabetes and gestational diabetes in this cohort of relatively young women in Alberta highlights a public health issue that requires monitoring and intervention.”