[Ovarian hyperstimulation in medically assisted reproduction: which practical approach?].

Ovarian hyperstimulation syndrome (OHS) with serious grade could be a live threatening disease, that occurs in 0.5% to 1% of in vitro fertilization program. The prevention of OHS is based on the recognition of risk factors and on ultrasonic and hormonal monitoring, with well adapted treatment in order to reduce the number of follicles. The level of oestradiol will determine the injection of human chorionic gonadotropins: between 2500 and 3000 pg/ml, the injection of HCG is reduced to 5000 U for the induction of ovulation, and the injections of HCG 1500 during the luteal period are avoided: between 3000 and 5000 pg/ml, the injection of HCG is reduced to 5000 U and the replacement of fresh embryos is deferred to an other cycle: after 5000 pg/ml, the injection of HCG must be abandoned. The treatment of the confirmed OHS is based on the rest, with hospitalization, correction of fluid, electrolyte and protein imbalance, prevention of thrombo embolism and aspiration of ascite fluid.