A small number of women having treatment to stimulate the ovaries (especially after IVF), will develop a problem called Ovarian Hyperstimulation Syndrome (OHSS). Overall, it affects between 0.6 – 14% of women, but only about 1-2% require hospital admission (i.e., in its severe form).
What is OHSS?
It is a combination of symptoms including enlargement of the ovaries, swelling and discomfort in the abdomen. It is often associated with nausea and vomiting which may lead to dehydration. In its severest form it can be life threatening hence the need for hospital admission.
Who is at risk?
Although we know the drugs you receive to stimulate your ovaries contribute to the development of OHSS, we do not as yet know why only a small number of women will go on to develop the syndrome. Some of the risk factors for its development include:
- presence of polycystic ovaries (PCOS)
- occurrence of OHSS in a previous treatment cycle
- high response to stimulation (>20 follicles before egg collection)
- Exposure to hCG and presence of pregnancy (especially a multiple pregnancy)
You are at a small risk for OHSS, if you have any one or a combination of the above factors.
When will I get symptoms?
Possible symptoms to expect are pain and swelling of the tummy, feeling sick, feeling dehydrated and passing a reduced amount of urine and diarrhoea.
The usual time to start getting symptoms is a few days after the egg collection or soon after the onset of pregnancy (if pregnant).
When will I get better?
If you are not pregnant, the symptoms will resolve completely once you have had a period. If you become pregnant, however, you may continue having problems until about the 2nd month of pregnancy before it then resolves.
Does it affect the chances of pregnancy?
This problem will have NO effect on your chances of pregnancy. Neither will it affect your pregnancy if you do become pregnant.
What treatment is given?
Prevention is obviously better than cure; the only guaranteed way to avoid OHSS is to cancel the cycle which unfortunately is a very high price to pay. We, however, do consider fertilisation and freezing of all your embryos which prevents conception and exposure of the ovaries to pregnancy hormones. Frozen or thawed embryos can then be transferred at a later date during a frozen embryo cycle.
However, the majority of patients who are considered to be at risk of OHSS only experience mild symptoms, if any, and can be managed at home. We would allow the cycle to proceed as planned but obviously keep a very close eye on you.
If the problem becomes severe however, you may need to come into hospital. Often, we simply need to give you pain killers, anti-sickness medication and encourage you to drink fluids, especially water and to rest. Specific treatment depends on your symptoms and may include daily blood tests, intravenous fluids (a drip) and heparin injections to thin the blood (this minimises the risk of blood clot formation). If you accumulate a lot of fluid in your tummy, it may cause you to feel breathless and uncomfortable; under these circumstances, we may drain the fluid away using a fine needle under ultrasound scan control (similar to an egg collection).
You should be rest assured that no aspect of the treatment you receive will affect your chances of pregnancy.
We would discuss all these options with you once we consider you to be at high risk for OHSS, so you can make an informed choice.
What do I do if I feel unwell?
You may develop some of the symptoms described above and feel worried. If you are concerned at any time, you should contact us directly on 0191 445 2768 (between 8am and 5pm, Monday – Friday). If after these hours please contact the hospital switchboard on 0191 482 0000 and ask for the IVF bleep holder, this will be one of the IVF Consultants. If they are unavailable another member of the IVF team will telephone you as soon as possible. Please, do not hesitate to contact us even if it’s simply for us to reassure you.