Ovarian hyperstimulation syndrome: imperatives for the emergency physician.

Ovarian Hyperstimulation Syndrome (OHSS) is a serious disorder complicating the use of ovary-stimulating drugs in assisted reproduction programs. While its pathogenesis is not fully understood, it is believed that human chorionic gonadotropin (hCG) stimulation is vital to the development of OHSS. Further evidence suggests that the renin-angiotensin pathway, vascular endothelial growth factor, endothelin-1, and cytokines all play a role in altering ovarian capillary permeability, leading to increased interstitial fluid. OHSS can produce a myriad of symptoms and signs involving numerous body systems, up to and including hypovolemic shock and acute renal failure. As growing numbers of women opt for assisted reproduction, it becomes increasingly important for emergency physicians to be able to recognize this condition. Clinical classification into mild, moderate, severe, and critical forms of OHSS can help the physician plan appropriate investigations, admission requirements, and acute management. Two cases of OHSS, representing the spectrum of this problem, are presented along with a review of the literature.