Very preterm newborns are more susceptible to changes in glucose levels (hypo- or hyperglycemia) during the first weeks post-partum. Achieving optimal glycemic control in this population is, however, still challenging, since adequate target glucose levels are still debatable in the community. Previous studies demonstrated a link between glucose levels and brain oxygenation, hypothesizing the presence of a cerebral glucose sensor, thus implying that glucose changes might affect brain and brain development. The effects of hypo- and hyper-glycemic changes on neurodevelopmental outcomes are, however, still controversial and studies so far have not included the direct effects of these glycemic changes on the preterm brain. The BabyGlucoLight project seeks to provide new insights on the relationship between glycemic changes and brain hemodynamics and on the impact of tight glycemic control on brain hemodynamics and neurodevelopmental outcome. We continuously monitored brain hemodynamics with diffuse optical tomography and glucose levels with continuous glucose monitoring during the first week post-partum in very preterm babies and followed them up until 24 months of age. In this seminar, I will describe the theoretical background and the outline of this clinical trial project. I will show some preliminary results of the relationship between glucose changes and brain hemodynamics and of the impact of glucose changes of brain functional connectivity and neurodevelopmental outcome.