Etiologies of Primary Ovarian Insufficiency

Primary ovarian insufficiency (POI) is a subclass of ovarian dysfunction in which the resting pool of primordial follicles is prematurely exhausted. It occurs through two major mechanisms: a pathologic process that causes follicle dysfunction or development of an inadequate initial pool of primordial follicles during embryogenesis. POI is a heterogeneous disease with variety of causes including genetic defects, autoimmunity, environmental factors, metabolic problems, and iatrogenic causes such as surgery, radiation, or chemotherapy. In over 90 % of cases the precise cause is unknown. In this chapter, we discuss the causes of POI to convey an understanding of disease pathophysiology.