Epidemiology and Prevention of Ovarian Hyperstimulation Syndrome (OHSS): a Review

Ovarian hyperstimulation syndrome (OHSS) is a rare iatrogenic complication of ovarian stimulation occurring during the luteal phase or during early pregnancy. Fortunately, the reported prevalence of the severe form of OHSS is small, ranging from 0.5 to 5%. Nevertheless, as this is an iatrogenic complication of a non-vital treatment with a potentially fatal outcome, the syndrome remains a serious problem for specialists dealing with infertility. The aim of this literature review was to determine whether it is possible to identify patients at risk, and which preventive method should be applied when an exaggerated ovarian response occurs. Data pertaining to the epidemiology and prevention of OHSS in women were searched using Medline, Current Contents and PubMed, and are summarized. Preventive strategies attempt either to limit the dose or concentration of hCG or to find a way to induce luteolysis without inducing a detrimental effect on endometrial and oocyte quality. The following particular preventive strategies were reviewed: cancelling the cycle; coasting; early unilateral ovarian follicular aspiration (EUFA); modifying the methods of ovulation triggering; administration of glucocorticoids, macromolecules and progesterone; cryopreservation of all embryos; and electrocautery or laser vaporization of one or both ovaries.