[Ovarian hyperstimulation syndrome--a risk of treatment for infertility]

Ovarian hyperstimulation syndrome (OHSS), a potential life-threatening condition the causative factor of which is unknown, comprises a spectrum of clinical symptoms and laboratory signs. The main risk factors for the development of OHSS include inherent ovarian sensitivity to ovulation induction agents, the use of exogenous hCG (human chorionic gonadotrophin) for ovulation induction or luteal phase support, and endogenous hCG production in early pregnancy. Since assisted reproduction entails achieving a delicate balance between controlled ovarian stimulation and hyperstimulation, complete elimination of the risk of OHSS is unlikely. However, it seems possible to reduce the frequency of severe cases by observing strict rules for its prediction and prevention, allowing early diagnosis and active treatment of manifest OHSS by correction of fluid and electrolyte imbalance, and aspiration of ascitic fluid if necessary.