[The ovarian hyperstimulation syndrome--diagnostic criteria, management procedures]

The ovarian hyperstimulation syndrome (OHSS) is still a difficult diagnostic and therapeutic problem. OHSS is associated with significant hypertrophy of the ovaries associated with the loss of the intravascular fluid to the third space which results in hypovolaemia, oliguria, electrolyte imbalance, and a rise in haematocrit. The endogenous OHSS is rare. Most often OHSS appears as a complication of induction of ovulation. The fundamental issue in pathophysiology of OHSS is an increase of capillary permeability which results in the leakage of fluid to the third space. The vascular endothelial growth factor--VEGF--is considered to be the factor directly responsible for the processes involved. The most common are the mild and moderate forms of the syndrome. The severe form of OHSS is a life-threatening condition. The following symptoms may be present: ascites, pleural and pericardial effusion, oliguria, dyspnoea with tachypnoe, tachycardia, adult respiratory distress syndrome, renal failure, venous thrombosis, ischaemic stroke, haemorrhage from a ruptured ovary. Therapy should be based on the correction of hypovolaemia, hypotension and oliguria. Antithrombotic prophylaxis is an integral part of the OHSS management. Some interesting attempts have been undertaken to re-infuse the protein-rich ascites fluid directly to the systemic circulation, so called continuous auto-transfusion system of the ascites (CATSA).