Trends in gestational diabetes in Manitoba from 1981 - 2019: A descriptive study with geospatial mapping.

Abstract

Background: There is little information describing trends in gestational diabetes incidence within sub-groups that often experience health inequities.

Methods: We leveraged provincial administrative health data to describe trends in gestational diabetes incidence between 1981-2019, stratified by sub-populations based on age, urbanicity, and neighbourhood-level average household income. We calculated yearly incidence across sub-groups and annual percent change in incidence to assess trends over time. Geospatial mapping was used to visualize changes by neighbourhood cluster.

Results: Gestational diabetes incidence increased from 1.3% to 8.6% between 1981 and 2019, with an upward inflection occurring around 2010. The annual percent change (APC) between 1981-2009, prior to the inflection point, was 1.9% (95% CI: 1.4-2.5%) and was 11.7% (95% CI: 8.9-14.7%) post inflection - from 2010-2019. After 2010, gestational diabetes incidence increased most among urban residents (APC= 18.1%; 95%CI: 13.9-22.5), among those >35 years (APC = 12.0%; 95% CI: 8.4-15.7%), and among individuals in the highest SES group (APC = 14.8%; 95% CI: 9.4-20.4%).Geospatial mapping showed that incidence increased more in neighbourhoods with the highest proportion of recent immigrants to Canada.

Conclusion: Incidence of gestational diabetes increased six-fold in Manitoba over the last 20 years, particularly among those with high SES and higher age. Further research is required to clarify the role of screening practices in the trends observed here.