Table 1.

Classification of OHSS symptoms[5] (adapted from Navot et al [9])

OHSS stage	Clinical features	Laboratory features
Mild	Abdominal distension/discomfort	No important alterations
	Mild nausea/vomiting
	Diarrhea
	Enlarged ovaries
Moderate	Mild features +	Elevated hematocrit (>41 %)
	Ultrasonographic evidence of ascites	Elevated WBC (>15000)
		Hypoproteinemia
Severe	Mild and moderate features +	Hemoconcentration (Hct >55 %)
	Clinical evidence of ascites	WBC >25000
	Hydrothorax	CrCl <50 mL/min
	Severe dyspnea	Cr >1.6
	Oliguria/anuria	Na+ <135 mEq/L
	Intractable nausea/vomiting	K+ >5 mEq/L
	Tense ascites	Elevated liver enzymes
	Low blood/central venous pressure
	Rapid weight gain (>1 kg in 24 hours)
	Syncope
	Severe abdominal pain
	Venous thrombosis
Critical	Anuria/acute renal failure	Worsening of findings
	Arrhythmia
	Thromboembolism
	Pericardial effusion
	Massive hydrothorax
	Arterial thrombosis
	Adult respiratory distress syndrome
	Sepsis

Cr = serum creatinine level; CrCl = creatinine clearance; WBC = white blood cell count.