What are the potential complications of OHSS that I should be aware of when managing these patients?

Ovarian hyperstimulation syndrome (OHSS) can lead to several serious complications that must be closely monitored during patient management. The primary complications include fluid shifts causing ascites and pleural effusions, which result from increased vascular permeability and third spacing of fluids. This can lead to hypovolemia and haemoconcentration, increasing the risk of thromboembolic events such as deep vein thrombosis and pulmonary embolism. Electrolyte imbalances, including hyponatraemia and hyperkalaemia, may also occur due to fluid shifts and renal impairment. In severe cases, patients may develop acute kidney injury secondary to hypovolemia and reduced renal perfusion. Other potential complications include ovarian torsion due to enlarged ovaries, respiratory distress from pleural effusions, and rarely, thrombotic microangiopathy. These complications necessitate careful clinical and laboratory monitoring, with particular attention to fluid balance, coagulation status, and renal function to prevent morbidity and mortality NICE CG156 Delvigne & Rozenberg 2003Avecillas et al. 2004Nelson 2017.