Ovarian hyperstimulation syndrome

Headline
Etiology Exogenous HCG used to stimulate (super)ovulation
Epidemiology risk factors: previous history of OHSS, young age, lean physique, polycystic ovary syndrome, and multiple pregnancies
Clinical presentation ascites, pulmonary oedema, hypovolaemia, renal failure, shock
massively enlarged ovaries
Pathogenesis vasoactive products released by hyperstimulated ovaries → ↑ capillary permeability
Diagnostic investigations hyponatraemia, hyperkalaemia
Serum osmolality (hypo-osmolality)
Liver function tests (elevated enzymes and reduced albumin)
Coagulation profile (elevated fibrinogen and reduced antithrombin)
Pelvis USS: enlarged ovaries
low serum IgG
Management emp abx
↑ risk pre-eclampsia

Severity criteria

Severe OHSS

Clinical ascites (± hydrothorax)
Oliguria (< 300 ml/day or < 30 ml/hour) Haematocrit > 0.45
Hyponatraemia (sodium < 135 mmol/l) Hypo-osmolality (osmolality < 282 mOsm/kg) Hyperkalaemia (potassium > 5 mmol/l) Hypoproteinaemia (serum albumin < 35 g/l)
Ovarian size usually > 12 cm

Critical OHSS

Tense ascites/large hydrothorax
Haematocrit > 0.55
White cell count > 25 000/ml
Oliguria/anuria
Thromboembolism
Acute respiratory distress syndrome