Gestational diabetes mellitus according to different diagnostic criteria: Prevalence and related factors

Gestational diabetes mellitus (GDM) has an impact on maternal health; however, there is no consensus about the diagnostic criterion and frequency of disease. The objective of this study was to estimate the prevalence of GDM and to evaluate the clinical characteristics of normoglycemic pregnant women and of those diagnosed with gestational diabetes mellitus, based on each criterion.

Prospective cohort study. Third-trimester pregnant women participated, with the occurrence of GDM being verified, according to two different diagnostic criteria. Prevalence was estimated in each category, and the prevalence ratios (PR) and 95% confidence intervals were adjusted using Poisson Regression.

A total of 8.7% of women were diagnosed with GDM (glycemia ≥95) and 8% had glycemic levels ≥92mg/dL according to IADPSG diagnosis. Factors related to the disease were the same, although the magnitude of the associations differed according to the diagnosis criteria. Pre-gestational obesity (PR 3.59 CI 1.28-10,07), previous diseases (PR 3.03 CI 1.15-7.94), and excessive weight gain (PR 4.71 CI 1.80-12.33) were factors related to total GDM, plus low nutritional knowledge (PR 3.17 CI 1.10-9.11). Regardless of the diagnostic criterion, women with GDM were at higher risk of intercurrences during pregnancy.

Nutritional knowledge and status were associated with GDM occurrence, independently of the diagnosis criteria. The adoption of the glycemic cutoff point of ≥ 92mg/dL indicated an important portion of the population without a diagnosis, suggesting that this cutoff point, more sensitive, should be used in order to guide women and minimize untoward outcomes.