The role of osmoregulation in the pathophysiology and management of severe ovarian hyperstimulation syndrome.

Severe ovarian hyperstimulation syndrome (OHSS), with an incidence of 1-2% of superovulation cycles, remains one of the most important complications of gonadotrophin use in assisted reproductive technologies because of its associated morbidity and rarely, mortality. Despite the wealth of scientific and clinical interest that this iatrogenic complication has generated, its pathophysiology is still not adequately elucidated and its management has thus remained empirical. Disorders of salt and water balance are two very important features that have been reported during severe OHSS. Some of the clinical and biochemical changes resulting from this disorder of salt and water balance are similar to those previously reported in pregnancy and liver cirrhosis. The pathophysiology of these clinical changes has been explained in part in pregnancy and liver cirrhosis by changes in osmoregulation function. It is this similarity in the clinical and biochemical changes in OHSS, pregnancy and liver cirrhosis that has prompted the investigation of the role of osmoregulation function in the pathophysiology of OHSS. The current article has been written to provide further details in support of recent excellent articles and guidelines, highlighting the physiological basis and rationale governing some aspects of, and the role of osmoregulation in the management of the OHSS syndrome.