Risk factors associated with the need for insulin in patients with gestational diabetes in a reference hospital in Buenos Aires, Argentina: retrospective cohort study

Objectives: To describe the clinical and sociodemographic characteristics of pregnant women diagnosed with gestational diabetes mellitus (GDM) and to assess factors potentially associated with out-of-target glycemic control and the need for insulin.

Materials and methods: Retrospective descriptive cohort. Women with GDM delivered at a reference hospital between January 2018 and September 2020 were included; women delivered in a different institution were excluded. Measured variables were age, body mass index (BMI) at the start of pregnancy, family history of diabetes, gestational age at the time of diagnosis, blood glucose levels at baseline and following oral glucose tolerance test, fructosamine, Hba1c, and insulin therapy use. A descriptive exploratory analysis of factors associated with poor glycemic control was conducted using uni and multivariate analyses.

Results: Of the patients with GDM, 44 % were out of target for blood glucose with lifestyle and dietary measures. The exploratory analyses revealed a potential increase in the risk of poor glycemic control associated with initial blood glucose level on OGTT (raw OR: 3.57; 95 % CI: 2.1 - 6.1), BMI > 25 kg/m2 (OR: 1.97, 95 % CI: 1.15 - 3.34), and more advanced gestational age at the time of diagnosis as a protective factor against the need for insulin therapy (OR: 0.45, 95 % CI: 0.27- 0.75). However, these associations were not confirmed in the multivariate analysis.

Conclusions: A baseline blood glucose value greater than 95 mg/dl and BMI of more than 25 kg/m2 could be associated with poor glycemic control in women with GDM. Studies that assess these variables and control for confounding factors are needed in order to identify the factors associated with insulin requirement in pregnant women.