Outcomes of Pregnancies Affected by Gestational Diabetes and Type 2 Diabetes in a Rural First Nations Obstetrical Program in Northwest Ontario

Progression From Gestational Diabetes Mellitus to Type 2 Diabetes Mellitus Among First Nations Women in Northwest Ontario: A Retrospective Cohort Study

OBJECTIVE

Our aim in this study was to identify the incidence of type 2 diabetes mellitus among First Nations women in northwest Ontario with a history of gestational diabetes mellitus (GDM).

METHODS

This work was a retrospective cohort study of women diagnosed with GDM using a 50-gram oral glucose challenge test or a 75-gram oral glucose tolerance test from January 1, 2010, to December 31, 2017, at the Sioux Lookout Meno Ya Win Health Centre. Outcomes were assessed based on glycated hemoglobin (A1C) measurements performed between January 1, 2010, and December 31, 2019.

RESULTS

The cumulative incidence of T2DM among women with a history of GDM was 18% (42 of 237) at 2 years and 39% (76 of 194) at 6 years. Women with GDM who developed T2DM were of similar age and parity and had equivalent C-section rates (26%) compared to those who did not develop T2DM. They had higher birth weights (3,866 grams vs 3,600 grams, p=0.006) and rates of treatment with insulin (24% vs 5%, p<0.001) and metformin (16% vs 5%, p=0.005).

CONCLUSIONS

GDM confers a significant risk for the development of T2DM in First Nations women. Broad community-based resources, food security, and social programming are required.

Systematic review of the use of metformin compared to insulin for the management of gestational diabetes: Implications for low-resource settings

Introduction

This systematic review examines the effectiveness of metformin treatment compared to insulin treatment for gestational diabetes within the context of a low-resource environment.

Methods

Electronic data searches of Medline, EMBASE, Scopus and Google scholar databases from 1 January, 2005 to 30 June, 2021 were performed using medical subject headings: 'gestational diabetes or pregnancy diabetes mellitus' AND 'Pregnancy or pregnancy outcomes' AND 'Insulin' AND 'Metformin Hydrochloride Drug Combination/or Metformin/or Hypoglycemic Agents' AND 'Glycemic control or blood glucose'. Randomized controlled trials were included if: participants were pregnant women with gestational diabetes mellitus (GDM); the interventions were metformin and/or insulin. Studies among women with pre-gestational diabetes, non-randomised control trials or studies with a limited description of the methodology were excluded. Outcomes included adverse maternal outcomes: weight gain, C-section, pre-eclampsia and glycaemic control and adverse neonatal outcomes: birth weight, macrosomia, pre-term birth and neonatal hypoglycaemia. The revised Cochrane Risk of Bias Assessment for randomised trials was used for the evaluation of bias.

Results

We screened 164 abstracts and 36 full-text articles. Fourteen studies met the inclusion criteria. The studies provide moderate to high-quality evidence demonstrating the effectiveness of metformin as an alternative therapy to insulin. Risk of bias was low; multiple countries and robust sample sizes improved external validity. All studies were from urban centres with no rural data.

Conclusion

These recent high quality studies comparing metformin to insulin for the treatment of GDM generally found either improved or equivalent pregnancy outcome and good glycaemic control for most patients, although many required insulin supplementation. Its ease of use, safety and efficacy suggest metformin may simplify the management of gestational diabetes, particularly in rural and other low-resource environments.

Demographics, prevalence and outcomes of diabetes in pregnancy in NW Ontario

Introduction

Diabetes in pregnancy confers increased risk. This study examines the prevalence and birth outcomes of diabetes in pregnancy at the Sioux Lookout Meno Ya Win Health Centre (SLMHC) and other small Ontario hospitals.

Methods

This was a retrospective study of maternal profile: age, parity, comorbidities, mode of delivery, neonatal birth weight, APGARS and complications. Data were compared to other Ontario hospitals offering an equivalent level of obstetrical services.

Results

Type 2 diabetes mellitus in pregnancy is far more prevalent in mothers who deliver at SLMHC (relative risk [RR]: 20.9, 95% confidence interval [CI]: 16.0-27.2); the rates of gestational diabetes (GDM) are double (RR: 2.0, 95% CI: 1.7-2.3). SLMHC mothers with diabetes were on average 5 years younger and of greater parity with increased substance use. Neonates largely had equivalent outcomes except for increased macrosomia, neonatal hypoglycaemia and hyperbilirubinaemia in GDM pregnancies.

Conclusion

Patients with diabetes in pregnancy at SLMHC differ substantially from mothers delivering at Ontario hospitals with a comparable level of service. Programming and resources must meet the service needs of these patients.