Based on the Hyperglycemia and Adverse Pregnancy Outcome study, new universal screening recommendations and cut-offs for gestational diabetes mellitus (GDM) have been proposed. In addition to the immediate perinatal risk, GDM carries an increased risk of metabolic disease in the mother and child. Maternal obesity has even been shown to be associated with increased all-cause mortality in offspring. In addition to known risk factors, excessive gestational weight gain, increased fat consumption, a low vitamin D level, psychological stress and negative mood are risk factors for GDM. Regarding therapy, the US Preventive Task Force concluded in 2013 that GDM treatment significantly reduces the risks of pre-eclampsia, macrosomia and shoulder dystocia (relative risks of 0.62, 0.5 and 0.42, respectively). Although nutrition therapy represents a cornerstone in GDM management, the results of studies are not clear regarding which types of dietary advice are the most suitable. Most physical activity interventions improve glucose control and/or reduce insulin use. Recent studies have evaluated and provided more information about treatment with metformin or glyburide. Postpartum management is essential and should focus on long-term screening and diabetes prevention strategies.