The Ovarian Hyperstimulation Syndrome.

The ovarian hyperstimulation syndrome (OHSS) is an iatrogenic syndrome, which may, infrequently, become severe and evenly fatal. Until the last decade, the worldwide popularity of assisted reproductive technology (ART) and ovulation induction/controlled ovarian hyperstimulation employed in ART for either in vivo fertilization or in vitro fertilization, in the last two decades, has been accompanied by an increase in the cases of OHSS. In the last decade, the substitution of the human chorionic gonadotropin trigger with the gonadotropin-releasing hormone agonist trigger has decreased the incidence of this syndrome but did not eliminate it completely. We summarize here the classification, pathophysiology, and treatment of the OHSS.