What is the Origin of OHSS?

This clinical syndrome is a recognized risk associated with Assisted Reproductive Technology (ART) procedures, particularly in vitro fertilization (IVF), where high doses of exogenous hormones are used to stimulate multifollicular development. The syndrome was first described as a consequence of using human menopausal gonadotropins (hMG) for ovulation induction.

What is the Mechanism of OHSS?

The central pathophysiological event is the massive release of vasoactive substances, primarily Vascular Endothelial Growth Factor (VEGF), from the stimulated ovaries in response to hCG. This leads to a dramatic increase in capillary permeability, causing fluid and protein to leak out of the blood vessels and into the peritoneal and pleural spaces. The resulting intravascular volume depletion causes hemoconcentration, decreased renal perfusion, and potential thromboembolic events, which are the main concerns in severe OHSS.

OHSS ∞ Area

OHSS

Meaning

Ovarian Hyperstimulation Syndrome, or OHSS, is an iatrogenic complication arising from controlled ovarian stimulation, characterized by an exaggerated, adverse systemic response to injectable gonadotropin or human chorionic gonadotropin (hCG) administration. This condition results in marked ovarian enlargement and, in clinically significant cases, the pathological shift of fluid from the intravascular space into the third space, such as the abdominal cavity. OHSS is classified by severity, ranging from mild bloating to critical, life-threatening systemic illness.