Implications of a new guideline on treating gestational diabetes in Denmark

Abstract

INTRODUCTION. In late 2023, the Danish national guideline on treatment of gestational diabetes mellitus (GDM) introduced tighter glucose control to prevent foetal and maternal complications. The change was expected to lead to an increased use of insulin therapy in GDM treatment. This study aimed to evaluate insulin usage and obstetric outcomes when adhering to the new guideline. METHODS. This retrospective cohort study evaluated women diagnosed with GDM (n = 67) from May to October 2024 at Gødstrup Hospital, compared with women diagnosed with GDM (n = 46) in a three-month period in 2023 before implementation of the new guideline. Data on maternal age, pre-pregnancy BMI, ethnicity, education, oral glucose tolerance test 2-h values, insulin treatment, induction of labour and foetal characteristics were collected. RESULTS. The number of women treated with insulin increased from 26% (2023) to 58% (2024), p < 0.01, but the maximum insulin dose did not change (0.42 IU/kg/day). Birthweight and birthweight z-scores were comparable. In 2024, induction of labour was more prevalent (63% versus 39%, p < 0.01) without a corresponding rise in obstetric and perinatal complications. CONCLUSIONS. Implementation of the new GDM guideline increased the number of women requiring insulin treatment but did not affect the maximum dose of insulin per kg. The increase in insulin treatment led to a higher labour induction rate, increasing the workload for the obstetric department. Our data showed no decrease in birthweight or the incidence of large-for-gestational-age offspring.