ovarian hyperstimulation syndrome

Question 1

what is OHS?

Answer 1

• associated with IVF and the use of HCG to mature the follicles in the final step of ovarian stimulation
• can also happen with the use of chlomifine in PCOS

Question 2

what is the pathophysiology of ovarian hyper-stimulation syndrome?

Answer 2

• hcg causes increased level of oestrogen and progestogens and also vasoactive substances like vascular endothelial growth factor (VEG-F)
• veg-F increases vascular membrane permeability and loss of fluid from the intravascular compartment
• it also affects the RAAS system-> an increase in renin correlates with the severity of the condition

Question 3

what are the risk factors for ovarian hyperstimulation syndrome?

Answer 3

Younger age
Lower BMI
Raised anti-Müllerian hormone
Higher antral follicle count
Polycystic ovarian syndrome
Raised oestrogen levels during ovarian stimulation

Question 4

how long after HCG injection does ovarian hyperstimulation occur?

Answer 4

• 7 days

- late onset can be from 10 days onwards

Question 5

how does ovarian hyperstimulation syndrome present?

Answer 5

• abdominal pain and bloating
• nausea and vomiting
• diarrhoea
• hypotension
• hypovolaemia
• ascites
• pleural effusions
• renal failure
• peritonitis from rupturing follicles releasing blood
• prothrombotic state-> can get DVT or PE

Question 6

how does mild avian hyperstimulation present?

Answer 6

• abdominal pain and bloating

Question 7

how does moderate ovarian hyperstimulation present?

Answer 7

• nausea, vomiting and ascites seen on USS

Question 8

how does severe ovarian hyperstimulation present?

Answer 8

• ascites
• low urine output
• low serum albumin
• high potassium
• raised haematocrit - when haematocrit goes up it indicates less fluid volume in the intravascular space

Question 9

how does critical ovarian hyperstimulation present?

Answer 9

• tense ascites
• anuria
• thromboembolism
• acute respiratory distress (ARDS)

Question 10

what is management of ovarian hyperstimulation syndrome?

Answer 10

• oral fluid
• monitor urine output
• low molecular weight heparin to prevent thromboembolism
• paracentesis for removal of ascites
• IV. colloids-> human albumin solution