A retrospective analysis of postpartum glucose testing incidence by prenatal care provider specialty in a Canadian gestational diabetes cohort.

Abstract

Background: Gestational diabetes mellitus (GDM) increases future risks of type 2 diabetes and cardiovascular disease. Despite Diabetes Canada guidelines recommending postpartum glucose testing following GDM, uptake remains low. Canadian population-based studies are needed to examine systems-level factors affecting uptake.

Methods: We used linked Alberta health datasets including births from 2017-2018 to identify prenatal care provider specialty (general practitioner (GP), obstetrician (OB), or midwife (RM)), postpartum glucose tests, and cohort demographics. Outcomes were 1) gold-standard testing: oral glucose tolerance test (OGTT) within 6 weeks to 6 months postpartum and 2) any glucose test within 6 weeks to 1 year. We used adjusted logistic regression modeling to estimate the association between test incidence and provider specialty.

Results: From 105,691 births we identified a cohort of 9,884 with GDM. Uptake of postpartum glucose testing was low: 22.2% (95% CI: 21.4 - 23.1) received gold standard testing and 53.9% (95% CI: 52.9 - 54.9) received any glucose test. When compared to the OB group, GP patients were less likely to receive both glucose test outcomes (OR_GS= 0.86, 95% CI: 0.77 - 0.95; OR_Any= 0.88, 95% CI: 0.81 - 0.96). Patients of RMs were also less likely to receive both glucose test outcomes (OR_GS= 0.67, 95% CI: 0.46 - 0.96; OR_Any= 0.88, 95% CI: 0.67 - 1.15).

Discussion: We report low postpartum glucose testing overall and found no clinically meaningful differences across provider specialties. The higher incidence of any glucose testing suggests that providers may be prioritizing alternative tests over the OGTT protocol for GDM patients.