A portrait of gestational diabetes mellitus in Brazil: A systematic review and meta-analysis.

The diagnostic criteria for gestational diabetes mellitus (GDM), a transient hyperglycemic state during pregnancy, has varied remarkably over time, resulting in a diversity of prevalence rates. The aim of this systematic literature review was to provide estimates of prevalence rates of GDM in Brazil according to different diagnostic criteria. We identified, reviewed, and extracted data from the scientific literature on studies estimating the prevalence of diabetes in pregnant women living in Brazil. The databases searched were PubMed, LILACS, SciELO, Embase, Web of Science, and Cochrane Library. We grouped studies by the source of information assessing GDM, patients' age, and criteria used to diagnose GDM. When three or more studies were available in a group, we calculated the pooled prevalence. The Joanna Briggs Institute (JBI) appraisal tool was used to assess the risk of bias. The data were reported according to the 2020 PRISMA recommendations. The study protocol was registered in PROSPERO. We identified 1,328 records and selected 21 studies involving 122,635 pregnant women. Studies in adults only, with primary data and laboratory measurements, and using the IADPSG criteria (n = 3) had a GDM prevalence of 18.0% (95% confidence interval [CI]: 16.0-20.1%) and included 6,243 participants. Estimates of self-reported GDM (n = 3; 10,136 participants of all ages) had a pooled GDM prevalence of 2.1% (95% CI: 1.5-5.2%), with high heterogeneity (I2 = 85.0%, p < 0.01). Studies including adolescents had consistently low prevalences. The prevalence of GDM in Brazil varied, was greater when the IADPSG criteria were applied, and depended on the methods used to obtain the GDM information and the age structure of the sample.