The ovarian hyper stimulation syndrome = OHSS is a rare complication which may occur during the hormonal stimulation in the course of an in-vitro fertilisation. However, basically  every form of hyper stimulation is rare and can be easily managed with practical or medical interventions. All important information and how to ideally prepare yourself can be found on this page.

Ovarian hyper stimulation syndrome or OHSS is a rare complication that results from stimulation during a fertility treatment. The manifestation of this syndrome can range from mild discomfort to, in rare cases, a serious illness for which hospitalization is required.

Different symptoms become apparent depending on the severity of the overstimulation. Precursors to these symptoms (e.g. abdominal distention, nausea) can also appear during a normal stimulation process and require no treatment.

Moderate form


  • Discomfort and minor pain, nausea, bloating sensation, discovery of ascites via ultrasound

Severe form


  • Nausea, vomiting, diarrhea, oliguria (changes in urinary excretion), abdominal pain/upper abdominal pain, breathing difficulties, diaphragmatic irritation, ultrasound showing enlarged ovaries and significant ascites, tension in the stomach as a result of the ascites

The treatment depends on the severity of the OHSS.

  • measures which can be applied at home (light forms)
    rest, increase in fluid intake (at least 3 to 4 liters per day), cool compresses on the abdomen (reduction of blood flow to the ovaries). An protein rich diet, as well as, protein drinks available in pharmacies (ie. Formitel) are also beneficial
  •  to combat the symptoms of OHSS and improve the well-being of the patient
    intravenous fluids, boosting the renal excretion of water, puncture to reduce pressure. The constant monitoring of symptoms is also necessary for the prevention of complications (monitoring of fluid excretion, waist circumference, blood parameters etc.). This is to ensure the prevention of severe complications, such as kidney failure or thrombosis.
  • Close, outpatient care or hospitalization (severe forms)
    If a severe form of OHSS occurs outpatient care or hospitalization may be required. This can be administered either in the gynaecological department of the Goldenes Kreuz (for patients with private insurance) or in the gynecological department of another hospital. In Vienna, the General Hospital (AKH), which is specialized in the treatment of OHSS, and the SMZOst are recommended.

Two forms of OHSS have been distinguished.

  • “early-onset”: usually occurs within a few days of the ovum pick-up procedure. The symptoms and complications decrease at the latest with the next menstruation if pregnancy does not occur.
  • "late-onset": is linked to hormone production at the onset of pregnancy and occurs about 8 to 17 days after the puncture procedure. It spontaneously improves with the reduction of progesterone (Corpus Luteum) activity. Their activity decreases in the 5th to 6th week of pregnancy.

If the symptoms of OHSS intensify after the ovum pick-up and may become severe we advise you to cancel the embryo transfer.

The embryos will be cryopreserved and can be used for a follow-up cryo cycle.