At “gennima”, all medication for ovarian stimulation is administered in personalised doses, i.e we modify the dose depending on the course of each patient’s cycle. As a result, in most cases, there are no side effects.
Rarely, the patient’s ovaries may overreact to medication, thus producing too many follicles; this is called “ovarian hyperstimulation”. In that case, the usual symptoms are nausea, vomiting and abdominal pain. “Ovarian Hyperstimulation Syndrome”, as it is called, may have mild, moderate or severe symptoms. How are all those symptoms caused?
During a natural cycle, women very often feel pain at ovulation, as well as bloating, swelling, irritability, breast pain or even mild depression before menstruation.
When medication is used to stimulate the ovaries, as in IVF, some women experience all of the above symptoms more intensely, because ovaries produce a large number of oocytes, instead of producing only one, as in the natural cycle.
In case all of the above symptoms become too intense and more symptoms occur (intense pain, nausea, vomiting), the patient is diagnosed with Ovarian Hyperstimulation Syndrome.
There are 3 categories, depending on the severity of the Syndrom:
• Mild Ovarian Hyperstimulation Syndrome – intense pain in the pelvic area. The patient must stay in bed for 1-2 days and modify her diet. Frequency: 1 cycle out of 30.
• Moderate Ovarian Hyperstimulation Syndrome – preventive hospitalisation of the patient may be deemed necessary. Frequency: 1 cycle out of 300.
• Severe Ovarian Hyperstimulation Syndrome – a great amount of fluid is concentrated in the abdominal area or the chest, which constitutes a very severe medical condition. Frequency: 1 cycle out of 1.000. However, such cases are extremely unusual in reliable IVF centres.
Ovarian Hyperstimulation Syndrome is a self-limiting condition and ovaries almost always return to normal. It mainly concerns patients with severe Polycystic Ovary Syndrome. Even then though, when stimulation is properly performed and regularly monitored, with dosage being adjusted as needed, it is unlikely that a problem will occur.
At “gennima”, we are proud that high pregnancy achievement rates are combined with particularly low incidence of ovarian hyperstimulation syndrome among our patients.
In the rare case that too intense OHSS symptoms lead to cancelling the IVF cycle, there is the possibility of embryo cryopreservation and embryo transfer in a future cycle, after symptoms subside.
Early and Late Ovarian Hypertimulation Syndrome
It has been found that ovarian hyperstimulation syndrome in patients on medication for ovarian stimulation occurs either early or late, while the factors triggering it are most probably different in each of the two cases.
Early ovarian hyperstimulation syndrome occurs 3-7 days after the administration of chorionic gonadotropin for final oocyte maturation before oocyte retrieval, while late OHSS occurs later on, 12 – 17 days after the administration of chorionic gonadotropin, and most of the times indicates pregnancy.
Early OHSS is related to ovarian overreaction during stimulation, while late OHSS depends on whether pregnancy is achieved and is more likely to be severe. Late OHSS is believed to be affected by increased chorionic gonadotropin due to pregnancy.