Ovarian Hyperstimulation Syndrome

This complication of ovulation induction is characterized by bilateral ovarian enlargement, ascites, intravascular volume depletion, weight gain, and hypotension. Severe cases can cause electrolyte imbalances, kidney failure, fluid collections around the heart or in the lung cavity, thickened blood, a tendency to clots, respiratory distress and rarely death. Milder forms of this syndrome occur in 2% to 25% of cases of ovulation induction using gonadotropins. Severe OHSS is seen in less than 2% of patients. This syndrome occurs more commonly in patients with polycystic ovarian syndrome. The syndrome usually occurs 3 to 10 days after hCG administration. Pregnancy can prolong the syndrome. If it appears that a patient is at risk for this syndrome, the ovulation induction regimen may be canceled.