Causes & Treatment

Could OHSS Wreck Your Chances of IVF Working?

Eloise Edington | 24 Jun 2021

Today on Fertility Help Hub, we hear from our fertility specialist partners, Unica Fertility Clinic, based in the Czech Republic, with over twenty-five years of specialist experience. They’re answering our Instagram reader questions on the topic of OHSS (Ovarian Hyper-Stimulation Syndrome). Read on to find out what OHSS is / how serious it is, how to prevent it and whether it affects fertility / IVF success.

Words by Unica Fertility Clinic

What is OHSS?

Ovarian Hyper-Stimulation Syndrome (OHSS) is where the ovaries are over stimulated, causing complications during the ovarian stimulation process – an imperative phase during IVF, for making mature eggs (called oocytes). OHSS has many symptoms that can contribute to the complication of the ovarian stimulation process, such as causing an accumulation of fluids in the abdomen.

The exact cause of this fluid transfer is unknown, but it is thought to be due to increased production of VEGF (vascular endothelial growth factor), which is produced by corpora lutea, formed after the oocyte draw.

The good news – today we can effectively prevent and change the emergence of OHSS with careful monitoring.

Preventing OHSS

In order to prevent OHSS, adequate doses of FSH must be administered. This is individualised dependent on AMH, AFC and weight. At Unica Fertility Clinic, our fertility specialists can also provide genetic testing, to check receptor’s sensitivity to FSH, and LH before starting your IVF cycle. Every part of the ovaries’ response to stimulation must be carefully followed by a fertility specialist, in order to ensure the safety of the patient.

If it looks as though OHSS is developing, we will look at postponing the cycle until the cavities have become normal and all clinical difficulties connected to OHSS have disappeared, depending on the severity of the OHSS.

Who is most at risk of developing OHSS and what are the recommended procedures to deal with it?

Once you have taken all of the prevention steps above and have removed all remaining indications of OHSS, the risk of getting it is low. Today it is a very minimal risk, affecting roughly 1-5% of women. More severe Ovarian Hyper-Stimulation Syndrome occurs only rarely, in less than 1% of stimulated women.

Women with Polycystic Ovary Syndrome (PCOS) and young women are particularly at risk of developing OHSS. Therefore, especially in these women, we use safer alternative procedures for the freezing of embryos after fertilisation of mature eggs, and we postpone the embryo transfer until the next menstrual cycle, when the patient is no longer at risk.

OHSS Symptoms

When the ovaries are stimulated, it is common for them to enlarge to a certain extent and at a certain pressure in the lower abdomen. With proper stimulation, this pressure subsides within two to three days after egg collection. When there is excessive egg production, the ovaries enlarge significantly, and, over time, fluid accumulates in the pelvis and abdominal cavity. Other symptoms then depend on the level of severity of the OHSS.

Severity of OHSS

The following are the severity levels of OHSS and resulting symptoms.

Symptoms of mild to moderate OHSS usually resolve within a week, if a woman becomes pregnant after a successful IVF implantation. The symptoms of OHSS may reappear as her body begins to produce its own hormones and HCG, during pregnancy. The following are symptoms of mild to moderate OHSS:

Persistent abdominal pain
Flatulence
Nausea
Vomiting
Diarrhoea
Ovarian tenderness

Symptoms of severe OHSS:

Rapid weight gain — more than 1 kg in 24 hours
Severe abdominal pain
Persistent nausea and vomiting
Blood clots
Decreased urination
Shortness of breath
Significantly enlarged abdomen

OHSS Effects on Fertility

OHSS does not have a direct effect on the quality of the eggs obtained and does not affect the chances of treatment / IVF success. For women with a significant risk of OHSS — for example women with PCOS — we also prevent the development of OHSS by freezing the embryos and postponing the IVF embryo transfer to the next cycle. The procedure of freezing embryos (cryopreservation) is now so gentle that the embryos can go through it without problems and without reducing the chances of IVF success, when having a frozen embryo transfer.

Treatment for OHSS

The mild form of OHSS usually gets better spontaneously within a few days. Treatment for OHSS is symptomatic and analgesics can be prescribed as a prevention of low molecular weight clots – Heparin (Fraxiparine, Clexane) is prescribed. The condition will completely disappear spontaneously within two -three weeks maximum.

However, if other symptoms develop, OHSS treatment is necessary. It consists of infusing fluid loss and the puncture of excess fluid from body cavities. Our fertility specialists would also administer Heparin (blood thinner) as a part of the treatment, as it prevents clots from forming.

Unica Fertility Clinic is our trusted partner clinic in the Czech Republic. They deal with all areas of fertility, including a range of infertility treatments and holistic care. If you’re concerned about developing OHSS during IVF or would like general fertility advice/ help, then reach out to the super friendly team at Unica Fertility Clinic today, for a fertility consult.

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