Ovarian hyperstimulation syndrome: a preventable syndrome?

Ovarian hyperstimulation syndrome (OHSS) is a dangerous and potentially life-threatening complication of controlled ovarian stimulation (COS). Although death has been rarely reported in extreme (or critical) cases, the syndrome is more often associated with debilitating and incapacitating symptoms. Considering that ovarian stimulation is performed on healthy uncompromised infertility patients and in healthy oocyte donors, every effort should be made to prevent or eliminate this complication. Although it has been generally accepted that OHSS is an inevitable and possibly unavoidable complication of COS, this issue of Seminars in Reproductive Medicine presents contemporary approaches for avoiding or virtually preventing this iatrogenic syndrome. Although the primary approach for avoiding OHSS should be the identification of the patient at risk and individualizing stimulation protocols, other post-stimulation strategies appear promising. In this issue of Seminars in Reproductive Medicine, we have invited a panel of world experts to share their experience and understanding of the pathophysiology of OHSS. Drs. Zivi, Simon and Laufer present a comprehensive description of the risk factors associated with OHSS along with a thorough review of various classification systems. Based on their extensive experience, they provide practical guidelines and approaches for treating patients at risk for developing OHSS. Dr. Gomez et al elegantly describe their experimental paradigms that have shed light on the pathophysiology of OHSS. Using a rat model, they demonstrated conclusively that the hyperpermeability found in OHSS is related to human chorionic gonadotropin (hCG)-mediated increased expression of vascular endothelial growth factor (VEGF) followed by activation of the VEGF2 receptor (VEGFR-2). Moreover, Zev Rosenwaks, M.D. Claudio Benadiva, M.D.