Ovarian hyperstimulation syndrome (OHSS) is a rare but serious complication, with moderate-to-severe cases reported in approximately 1–5% of in vitro fertilization (IVF) cycles. Primary prevention involves classifying patients based on their risk factors for OHSS and individualizing treatment protocols to adjust dosing for those at risk, thereby preventing severe manifestations of the syndrome. Secondary prevention aims to prevent progression to OHSS in patients who exhibit an excessive response to ovarian stimulation. While consideration of risk factors and preventive strategies has contributed to a reduction in the probability and severity of OHSS, these measures do not eliminate the risk entirely. Consequently, biochemical markers have been proposed as additional tools for early assessment and potential treatment targets for OHSS. Established ovarian biomarkers, such as anti-Müllerian hormone (AMH) and estradiol, are already utilized in clinical practice. Vascular endothelial growth factor (VEGF) is another critical biomarker implicated in the pathogenesis of OHSS and has been targeted by various pharmacological agents, including cabergoline. Identification of novel biomarkers is essential for enhancing early prevention strategies for OHSS. Recent studies have investigated new biochemical markers and proteins that may be involved in the theoretical pathophysiology of OHSS, proposing them as potential treatment targets alongside VEGF. However, the current evidence primarily remains theoretical, with no single biomarker demonstrating superiority or providing robust evidence for routine clinical application. Further clinical research is necessary to validate these findings and support their integration into clinical practice.