The maturation of functional eggs in the ovaries is a critical process during reproduction. However, the underlying mechanisms driving follicle growth remain enigmatic. In this talk, I will present new findings that the contractile surface cells of follicles can exert compressive stress to impact oocyte signalling and follicle growth, and regulate follicle growth competition in assemblies. I will also report the role of cell death and interfacial tension in driving critical behavior of luminogenesis during follicle development. Our studies highlight the importance of mechanical stress and hydraulics in ovarian dynamics, and the need of a biophysical approach to understand these fundamental stage of reproduction.