A Retrospective Analysis of Postpartum Glucose Testing Incidence by Prenatal Care Provider Specialty in a Canadian Gestational Diabetes Cohort.

OBJECTIVES

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

METHODS

We used linked Alberta Health data sets, including births from 2017 to 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, which is oral glucose tolerance testing (OGTT) within 6 weeks to 6 months postpartum; and 2) any glucose test within 6 weeks to 1 year. We used adjusted logistic regression modelling 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% confidence interval [CI] 21.4% to 23.1%) received gold standard testing and 53.9% (95% CI 52.9% to 54.9%) received any glucose test. When compared with the OB group, GP patients were less likely to receive both glucose test outcomes (odds ratio [OR]GS=0.86, 95% CI 0.77 to 0.95; ORAny=0.88, 95% CI 0.81 to 0.96). Patients of RMs were also less likely to receive both glucose test outcomes (ORGS=0.67, 95% CI 0.46 to 0.96; ORAny=0.88, 95% CI 0.67 to 1.15).

CONCLUSIONS

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.