Ovarian hyperstimulation syndrome (OHSS) is a problem associated with IVF. It occurs when the ovulation-inducing drugs taken during the first part of the treatment procedure make the ovaries leak fluid and become swollen. Although around 1/3 of IVF patients will be affected by OHSS in some way, very few of these cases, in fact it could be less than 2%, can be classed as "severe." Severe OHSS is a potentially life-threatening medical emergency and must be treated by a doctor. Patients suffering from severe OHSS will probably require hospitalization.
Mild OHSS symptoms usually last around a week. If they go on for longer, they are classed as "moderate," and if they carry on for even longer, or worsen rapidly, they are considered severe. If you're not a medical professional, it can difficult to determine whether your symptoms are mild or serious, so you must allow a doctor to monitor you while you are suffering from OHSS.
Mild symptoms generally include:
- Discomfort, pain and swelling in the abdomen
- Nausea and vomiting
- Bowel problems (constipation and diarrhea)
- Dark, syrupy urine
Moderate to severe symptoms include:
- Gaining weight at a very fast pace (for example, 5 to 10 pounds in just a couple of days)
- Having difficulty catching your breath
- Severe and persistent nausea and vomiting
- Urinating a lot less often than usual
Other severe OHSS symptoms are similar to mild OHSS symptoms but more intense - severe pain in your abdomen; tightness and swelling around the area of your ovaries; problems moving your bowel; and passing very dark, very thick urine.
See a doctor immediately if you have these severe symptoms. Go to the emergency room if your doctor is not contactable.
If left untreated, severe OHSS can lead to thrombosis (blood clots in your arteries or veins), liver and kidney disorders, and problems with lung function. These are all vital organs, which means that although it's extremely rare, severe OHSS does have the potential to kill. That's why it's so important that patients suffering from mild OHSS keep a close eye on their symptoms and maintain good communication with their doctors until their symptoms disappear.
Another possible complication of OHSS is the rupture of an ovarian cyst. That's why you should avoid strenuous physical activity and sexual intercourse while you have the condition. Regular, moderate exercise is, however, recommended because it keeps your blood flowing and helps to avoid dangerous blood clots.
Monitoring OHSS usually takes the form of physical and ultrasound examinations, to check the swelling in your ovaries. There is no "test" as such to diagnose mild, moderate or severe OHSS.
Some women are reluctant to bring symptoms to the attention of their doctors because they're worried that the fertility specialists may decide to stop the IVF treatment. The dangers of hiding OHSS symptoms from doctors are obvious, never mind the fact that the likelihood of being able to do so amid all the testing involved in IVF is very small. In any case, it's usually possible for IVF treatment to continue if OHSS symptoms resolve themselves. If not, treatment will be required - see our section on OHSS treatment for more information.