Background: Gestational diabetes (GDM) is a major risk factor for adverse pregnancy outcomes and the best screening strategy is still debated. OBJECTIVE We aimed to assess the prevalence of adverse outcomes in a cohort of women diagnosed following universal screening. Patients and Methods: We conducted a retrospective single-center study among 1287 women diagnosed with GDM adopting a universal screening strategy. Main adverse outcomes were evaluated. Results: If following the Italian recommendations for selective screening, we would have missed nearly 9% of GDM diagnoses. Women with an early diagnosis (16-18 GW) more often belonged to high-risk ethnicities and showed an increased frequency of caesarean delivery, fetal growth restriction and need of insulin therapy, but they were less likely to experience excessive gestational weight gain. Multivariate analysis demonstrated that poor glycemic control across all visits was an independent predictor of neonatal macrosomia (OR 2.23, p=0.014), while good glycemic control at last visit was protective against neonatal hypoglycemia (OR 0.41, p=0.005); insufficient gestational weight gain was associated with neonatal hypoglycemia (OR 2.22, p=0.015). Interestingly, an early diagnosis was independently associated with neonatal cardiac hypertrophy (OR 2.47, p=0.045), whereas insulin therapy was not independently associated with adverse outcomes. Conclusions: Extending GDM screening and achieving adequate metabolic control during the whole pregnancy, may help reducing adverse neonatal outcomes.