Ovarian hyperstimulation syndrome

: The author discusses the etiology and pathophysiology of the Ovarian Hyperstimulation Syndrome (OHS) and its relationship with Polycystic Ovarian Disease, in which it occurs more frequently. He presents the clinical histories of five patients who, in a period of two years, developed this syndrome in three different degrees of severity, while undergoing therapy for ovulatory infertility. The clinical history of one patient, who developed the most severe manifestations of OHS, is discussed in detail. The author emphasizes the difficulties that can be faced in trying to prevent the OHS, particularly because of probably inherited characteristics which may explain why not all patients with the same risk factors develop the OHS.