Abstract Objectives To evaluate the indirect effects of the COVID-19 pandemic on the care of women with pregnancies complicated by gestational or pre-existing diabetes, and their maternal-fetal outcomes. Methods A cross-sectional panel data conducted in a University Hospital in Southern Brazil. Maternal-fetal outcomes and predictors of care from 235 pregnant women with type 1, type 2, or gestational diabetes were evaluated. Two time periods were compared: six months preceding the pandemic, in 2019, and the COVID-19 period from September 2020 to March 2021. Comparisons were performed using analysis of variance, Mann–Whitney U, Fisher’s exact and T-tests. Risks were calculated using the Poisson regression with robust estimates. Results Maternal age was lower (32.1 ± 6.8 vs. 34.4 ± 6.6, p=0.009) and rates of depression/anxiety were higher (16.5 vs. 7.4%, p=0.046) in the group evaluated during the COVID-19. Neonatal hypoglycemia (RR 4.04; 95% CI 1.37–11.98, p=0.012), and SGA rates (RR 4.29; 95% CI 1.93–9.54, p<0.001) were higher in the group assessed before the pandemic. Conclusions Despite economic, social and structural impacts of the pandemic, parameters of maternal care were similar; diabetes control improved, and neonatal hypoglycemia and SGA rates were lower among pregnant women with diabetes during the pandemic.