Ovarian hyperstimulation syndrome (OHSS) is a serious, detrimental, and unintended consequence of controlled ovarian stimulation (COS) due to excessive ovarian stimulation, excessive ovarian response to COS, or the use of human chorionic gonadotrophin (hCG) for triggering ovulation. There are useful predictive tools and several preventive interventions aimed at reducing the occurrence of OHSS. Interventions for unexpected ovarian hyperstimulation syndrome (OHSS) include stopping gonadotropin injections, increasing fluid intake with electrolyte-rich drinks, closely monitoring vital signs, performing abdominal ultrasound monitoring, considering paracentesis to drain excess abdominal fluid in severe cases, and in some situations, using medications like cabergoline to reduce fluid accumulation; for prevention in future cycles, strategies like embryo freezing, adjusting gonadotropin dosages, and using a gonadotropin-releasing hormone (GnRH) agonist trigger instead of hCG may be implemented, depending on the severity of OHSS.