One of the fears of women looking for IVF treatment is the risk of Ovarian Hyperstimulation Syndrome (OHSS). If you have heard about this topic before but are still unsure what this syndrome is and how you can deal with it, reading this article may help clarify your ideas. 

What is OHSS? 

It is an excessive reaction of the ovaries to the stimulation process preceding IVF. Thus, women who opted for egg donation treatment will not have to think about this issue, given that the egg donor will undergo stimulation. However, IVF treatments with a woman's own oocytes involve stimulation of the future mother. OHSS occurs because ovaries may keep responding to the medication even after patients have stopped taking medications. But what happens practically? 

The symptoms of OHSS:

In reality, OHSS translates into a feeling of pressure in the lower abdomen ("abdomen fullness"). This may happen because of fluid accumulation in the abdomen. Although we do not know the precise cause behind this event, experts believe that the trigger may be an increase in the production of vascular endothelial growth factor produced by the corpus luteum after oocyte retrieval. 

When symptoms are mild to moderate, they may include pain in the abdomen and/or vomiting, diarrhoea, nausea, but they typically last no more than one week. More severe symptoms may include blood clots, a significant enlargement of the abdomen, blood clots, and/or speedy weight gain. If patients experience these symptoms, they should contact their doctor, who will take care of the issue through effective treatment. 

How common is OHSS? 

If patients follow the suggested prevention measures, they incur a very low risk of OHSS, which decreases to less than 1% of cases for severe symptoms. Prevention includes:

- Administering the correct doses of FSH according to each woman's situation

- Opting for genetic testing

- Postponing the following IVF cycle until all signs of OHSS have disappeared. 

Does OHSS affect pregnancy chances? 

As doctor Frgala explains, not anymore. About ten years ago, there was a need to freeze the embryos when hyperstimulation occurred, which was a stressful procedure for the embryos themselves. However, cryopreservation processes are much more gentle nowadays. Therefore it can be performed in the case of OHSS, and the transfer can be postponed by one or two months. There is no reason to think that chances will be lower due to this syndrome when transfer actually occurs. 

If you have any more questions about the topic, please feel free to contact our coordinators, who will be happy to answer all of your questions. At Unica, we want to make you feel as reassured as possible during the whole IVF journey.