IVF and Hyperstimulation Syndrome

Hyperstimulation syndrome, also known as ovarian hyperstimulation syndrome, is a consequence of the fertility medications needed to successfully conduct an IVF cycle. As IVF makes use of sex cells generated by the body, drugs are used to induce the production of eggs in women, and it is this end of the process that can sometimes lead to ovarian hyperstimulation syndrome.

What causes ovarian hyperstimulation syndrome?

The main fertility drug associated with hyperstimulation syndrome is a hormone which is naturally produced by your body during pregnancy called human chorionic gonadotropin, a mouthful often shortened to hCG. This hormone is needed in the preparation for IVF as it triggers the release of eggs which are then collected for IVF in a process called ovarian stimulation.

What are the symptoms of ovarian hyperstimulation syndrome?

The extent of the condition tends to vary considerably and symptoms are organised according to severity in three categories, severe, moderate, and mild.

Mild symptoms of ovarian hyperstimulation syndrome: Nausea, some weight gain, bloating and fullness in the abdomen, and diarrhoea.
Moderate symptoms of ovarian hyperstimulation syndrome: Considerable weight gain (defined as more than 2 pounds or 0.9 kg a day), smaller amounts of darker urine, diarrhoea, vomiting, dryness in the skin and hair, constant thirst.
Severe symptoms of ovarian hyperstimulation syndrome: Fullness and bloating, calf and chest pains alongside shortness of breath, lower abdominal pain, vomiting, diarrhoea, dramatic weight gain, and extremely dark urine in small quantities if any at all.

As the list above shows the condition can become quite severe, and its effects extremely unpleasant. A number of clinical tests are conducted to confirm which form of the syndrome you might be suffering from.

What happens during ovarian hyperstimulation syndrome?

Ovaries swell during hyperstimulation syndrome, and are associated with the many symptoms listed above. The condition tends to fade within 2 weeks of its onset unless you are pregnant, in which case the condition can be more severe and last longer. This is because the causative hormone, hCG, is produced during pregnancy and worsens your condition. If you are pregnant and afflicted with really severe ovarian hyperstimulation syndrome, then the duration of the illness can vary but tends to be within the first trimester.

The syndrome involves the formation of cysts in the ovaries, these fluid filled sacs cause the ovaries to swell and enlarge leading to the other symptoms. Although this is in fact typical of anyone going through ovarian stimulation, ovarian hyperstimulation syndrome also involves the movement of fluids into the abdominal space, causing the above symptoms.

How is ovarian hyperstimulation syndrome treated?

How the syndrome is treated depends on how severe the condition and the symptoms are. Mild ovarian hyperstimulation treatment just involves getting you to come in and have any symptoms treated and monitored, while the moderate form of the illness involves much closer observation, replenishment of fluids lost through diarrhoea and vomiting, and lot of bed rest.

The more severe form of the condition will often need the measures mentioned above for the moderate illness, on top of pain relief and the removal of unwanted fluid if it is causing breathing problems or too much pain. If ovarian hyperstimulation syndrome develops as part of IVF, then it is likely that your doctor will decide to delay implanting any embryos as pregnancy will worsen your condition

How can I prevent ovarian hyperstimulation syndrome?

Preventing the syndrome is more down to your doctor than you, as it revolves around administering the hormones involved in ovarian stimulation carefully and with close monitoring. A new type of drug that achieves the effects of hCG is called a GnRH agonist, and using this medication rather than hCG means that there is no risk of developing ovarian hyperstimulation syndrome, but there is a slight drop to the chances of a successful pregnancy (about 6%).

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