What is Ovarian Hyperstimulation Syndrome? As part of their fertility treatment many women take medication by tablets or injections to stimulate their ovaries to produce many egg sacs (follicles). Sometimes there is an excessive response to fertility drugs and this causes Ovarian Hyperstimulation Syndrome (OHSS). Overstimulated ovaries enlarge and release chemicals into the bloodstream that make the blood vessels leak fluid into the body. Fluid leaks into your abdomen, and in severe cases, into the space around the heart and lungs. OHSS can affect the kidneys, liver and lungs. A serious but rare complication is a blood clot (thrombosis). What are the symptoms of OHSS? The symptoms include abdominal swelling or bloating due to the enlarged ovaries, nausea and as the condition get worse, vomiting. Mild OHSS - mild abdominal swelling or bloating, abdominal discomfort and nausea. Moderate OHSS symptoms of mild OHSS but the swelling and bloating is worse because fluid is building up in the abdomen. There is abdominal pain and vomiting. Severe OHSS Symptoms of moderate OHSS plus extreme thirst and dehydration because so much fluid is building up in the abdomen, passing very small amounts of concentrated urine, difficulty breathing because of the build up of fluid in the chest and a red, hot, swollen and tender leg due to a clot in the leg or lungs (thrombosis). Who gets OHSS? Mild symptoms are common in women having IVF treatment. As many as one in three (33%) women develop mild OHSS. About one in 20 (5%) women develop moderate or severe OHSS.

The risk of OHSS is increased in women who:

have polycystic ovaries

have had OHSS previously get pregnant, particularly if it is a multiple

pregnancy (twins or more) How long does OHSS last? Most of the symptoms should resolve in a few days. If you have mild OHSS you can be looked after at home. If your fertility treatment does not result in a pregnancy, OHSS will get better by the time your period comes. If your fertility treatment results in a pregnancy, OHSS can last up to a few weeks or longer. What should I do if I have mild OHSS? Make sure you drink clear fluids at regular intervals. Make sure you do not drink in excess. If you have pain, take paracetamol or codeine (no more than the maximum dose). Even if you are tired, make sure you continue to move your legs to prevent blood clots. When should I call for medical help? Call for medical help if you develop any of the symptoms of severe OHSS, particularly if you are in pain despite taking pain relief. If you start to vomit, have urinary problems, chest pain or any difficulty breathing. When will I need to stay in hospital? There is no specific test that can diagnose OHSS. A diagnosis is made on the basis of your symptoms. Your doctor will ask you to describe your symptoms and will examine you. In addition your doctor may order:

Blood tests to check your Kidney, Liver and clotting functions

You will be weighed and your abdomen measured. This is to confirm if fluid is building up or reducing.

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Ovarian Hyperstimulation Syndrome Patient Information Womens Health Service, Wellington Hospital

Fluid intake and output (how much you

drink and how much urine you pass) will be monitored.

Ultrasound scan of your ovaries to measure how big they are and whether there is any fluid build-up in your abdomen.

The management of your care will depend on the severity of the symptoms. What is the treatment for OHSS? There is no treatment that can reverse OHSS. OHSS will get better with time, so treatment is to help symptoms and prevent problems. This includes:

Medication to control nausea and vomiting. This can be given either as a tablet to take by mouth or by an injection into an IV line in your arm/hand.

Analgesia can be given for discomfort or pain caused by the symptoms of OHSS. Anti-inflammatory pain relief such as voltaren should be avoided as it can cause bleeding. Medication that is given in the hospital will be safe for your unborn child should you have an early pregnancy.

You will be given a pair of anti-thrombo-embolism stockings (called TED stockings) to help prevent blood clots developing in your legs or lungs. This is because the disturbance in liver function can affect your blood clotting mechanism putting you at a higher risk of developing blood clots. You may also be given an anti-clotting injection into the skin of your abdomen once a day to reduce the risk of clotting.

You will be asked to exercise by walking in the ward as well as moving your legs and feet in bed. This will help blood circulation.

An intravenous(IV) line is inserted into a vein in your arm or hand to give fluid to help keep you hydrated. The fluid shift caused by OHSS means that although you have excess fuid in your abdomen, this fluid has shifted from your circulation. As a result, the fluid in your circulation will decrease causing dehydration and making you thirsty.

There may be a restriction placed on your overall fluid intake. This would allow you

no more than 2-3 litres of total fluid intake over a 24 hour period.

If you have difficulty in passing urine, or if you are passing significantly reduced amount of urine, a catheter may need to be placed in your bladder. This will enable the staff to accurately record the amount of urine you are passing.

In rare cases where there is a large amount of fluid in the abdomen causing significant discomfort, a procedure called paracentesis may be offered.This involves a cannula (a thin tube) being inserted into the abdominal wall to drain off the excess fluid.

A paracetesis will only be considered in severe OHSS because it cannot stop the fluid being collected in the abdominal wall. As with any other procedure there are risks involved. Should a paracentesis be recommended the dictor will discuss the procedure with you first. Paracenthesis will only provide temporary relief and fluid may accumalate again causing furter discomfort. Is my baby at risk if I have OHSS? There is no evidence of problems in the baby as a result of having OHSS. Leaving Hospital You will be discharged from hospital once your condition has improved and you are well enough to go home. Contact details Womens Clinics-Acute Assessment Level 3 North Wellington Hospital Phone 04 8060 740 Ward 4 North (Pod A Gynaecology) Level 4, Wellington Hospital Phone 04 8060 881 (Extension 80881)

GA PIB-37 Issued April 2013 Review April 2016 Page 2 of 2