A limiting factor of a system relying on spontaneous microvessel formation is the inability to precisely quantify the development of the microvessel network and control fluid moving through formed vessels. Herein, we report a strategy to monitor the dynamic formation of microscale fluid networks. The non-invasive, non-destructive monitoring and characterization of the fluid network is achieved via in-line sensing of fluid flow rate and correlating this measurement to the hydrodynamic resistance of the fluid network.