Table 1.

OHSS classification

Severity	Clinical signs	Biochemical markers
Mild	Abdominal discomfort
	Mild nausea/vomiting	No clinically significant
	Diarrhea	laboratory changes observed
	Enlarged ovaries
Moderate	Sonographic signs of ascites	Hemoconcentration (hematocrit >41%)
		Leukocytosis (>15,000/ml)
		Hypoproteinemia
Severe	Ascites
	Severe abdominal pain	Hemoconcentration (Ht>55%)
	Severe nausea and vomiting	Leukocytosis >25,000/ml
	Rapid weight gain (1 kg or more in 24 hours)	Serum creatinine >1.6 mg/dL
	Pleural effusion	Creatinine clearance <50 ml/min
	Severe shortness of breath	Hyponatremia (<135 meq/l)
	Oliguria/anuria	Hyperkalemia (>5 meq/l)
	Hypotension/low central venous pressure	Elevated liver enzymes
	Fainting
	Venous thrombosis
Critical	Anuria/acute renal failure	Deterioration of biochemical parameters
	Arrhythmia
	Pericardial effusion
	Massive hydrothorax
	Thromboembolism
	Arterial thrombosis
	Acute respiratory distress syndrome
	Sepsis