Table 1 Classification of OHSS symptoms[5] (adapted from Navot et al [9])

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