ObjectiveThe present study aims to compare the maternal and fetal outcomes of parturients with and without a gestational diabetes diagnosis.MethodsA case-control study including parturients with (cases) and without (control) a gestational diabetes diagnosis, who delivered at a teaching hospital in Southern Brazil, between May and August 2018. Primary and secondary data were used. Bivariate analysis and a backward conditional multivariate logistic regression were used to make comparisons between cases and controls, which were expressed by odds ratio (OR), with a 95% confidence interval (95%CI) and a statistical significance level of 5%.ResultsThe cases (n= 47) were more likely to be 35 years old or older compared with the controls (n= 93) (p< 0.001). The cases had 2.56 times greater chance of being overweight (p= 0.014), and a 2.57 times greater chance of having a positive family history of diabetes mellitus (p= 0.01). There was no significant difference regarding weight gain, presence of a previous history of gestational diabetes, height, or delivery route. The mean weight at birth was significantly higher in the infants of mothers diagnosed with diabetes (p= 0.01). There was a 4.7 times greater chance of macrosomia (p< 0.001) and a 5.4 times greater chance of neonatal hypoglycemia (p= 0.01) in the infants of mothers with gestational diabetes.ConclusionTherefore, maternal age, family history of type 2 diabetes, obesity and pregestational overweightness are important associated factors for a higher chance of developing gestational diabetes.