Ovarian hyperstimulation syndrome causes, risks and treatment
What Causes OHSS?
The exact causes of OHSS are not known but it is thought that the high levels of oestrogen, progesterone and the pregnancy hormone (HCG) are responsible and affect the way fluid is distributed around the body.
Severe forms of OHSS are very rare and occur in less than 1% of all cases.
Who is most at risk from OHSS?
Every patient undertaking treatment is potentially at risk. There are, however, several specific groups who are at greater risk:
- Younger women- the exact reason is unknown
- Women with polycystic ovaries
- Women with multiple and excessive enlargement of follicles in their ovaries- these women who have ‘over-stimulated’ to the drug treatment are at higher risk because this will cause their hormone levels (mainly oestrogen) to be excessively high
- Women who become pregnant must also watch for signs of OHSS as it quite often manifests after successful treatment.
What steps does the unit take to make sure I am safe?
The safety of patients is of paramount importance to us. Steps are taken to ensure the syndrome does not develop:
- The development of follicles is monitored using ultrasound scanning and hormone levels are assessed through blood tests.
- In cases where a patient develops too many follicles or has abnormally high hormone levels we stop treatment and advise the use of barrier contraception.
- For IVF/ICSI patients, in cases that are not severe, the egg collection may go ahead with any embryos produced being stored for later use rather than being replaced in the same cycle, thereby allowing recovery from the condition.
- In less severe cases the centre may ‘coast’ patients by stopping injections, and wait to see if symptoms improve before egg collection.
- In some cases an egg collection may be performed and all embryos may be stored straight after fertilisation for use at a later date.
What treatments are there for?
Usually mild OHSS will settle down on its own if drug treatment is stopped for 2-3 weeks.
Pain can be treated with aspirin or paracetamol. In more severe cases the patient is usually admitted to hospital where they are carefully monitored and put on a drip to keep their fluid balance correct.
If you have any significant symptoms similar to those described on the OHSS Symptoms page then please contact the Fertility Centre on (01743) 261202 or out of normal office hours the Gynaecology ward (01743) 261210.
In the unlikely event you are unable to contact either of the above you should contact your G.P. Explain what treatment and drugs you are on and your symptoms.