The effect of service concentration on outcome quality of inpatient services in the hospital sector is debated, and is particularly important in the field of obstetrics. The aim of this article was to investigate the influence of volume-outcome factors and competitive economic parameters on the quality of outcomes in obstetric departments of German hospitals. In this study, structural and performance data on 412 German hospitals in 2021 were analyzed with a quantitative research approach. To test the hypotheses, a polynomial multiple regression model with a total of eleven independent variables was estimated. Newborn mortality was used as an indicator of outcome quality in obstetrics departments. Contrary to expectations, the competitive economic parameters that are important for births play a rather subordinate role, while strong empirical evidence was found for volume-outcome relationships. The results of this study suggest that positive quality effects of service concentrations also predominate in the field of obstetrics and thus provide evidence in support of the forthcoming hospital reform in Germany.