Ovarian hyperstimulation syndrome [OHSS ], usually occurs as a result of taking hormonal medications that stimulate the development of eggs in a woman’s ovaries. These injectable fertility drugs may be prescribed to treat infertility. In ovarian hyperstimulation [HS] syndrome, your ovaries become swollen and painful.
About one-fourth of women who take injectible fertility drugs get a mild form of ovarian HS syndrome, which goes away after about a week. If you become pregnant after taking one of these fertility drugs, however, your symptoms of ovarian HS syndrome may last several weeks. A small proportion of women taking fertility drugs develop a more severe form of ovarian HS syndrome, which can cause
• rapid weight gain,
• abdominal pain,
• vomiting and
• Shortness of breath.
• Woman in pain.
What then is OHSS?
OHSS is the most serious consequence of induction of ovulation, as part of assist conception techniques.
It may occur after stimulation of the ovaries into superovulation with drugs such as human chorionic gonadotrophin (hCG) and human menopausal gonadotrophin [hMG]. It is rare with clomifene except in polycystic ovarian syndrome (PCOS).
It is important to note that, because this condition may occur may occur unexpectedly, therefore many women with OHSS will be seen by doctors unfamiliar with the condition. This is because assisted conception treatment frequently takes place outside hospitals and also because serious OHSS is uncommon. Education and good communication are particularly important in providing safe and effective care to women with this condition.
OHSS is the most serious complication of infertility treatment, particularly IVF. Any patient undergoing ovulation induction is at risk of developing OHSS, although some are at more risk than others. Severe OHSS is a life threatening complication following ovarian stimulation
FREQUENCY OF OCCURRENCE :
Despite the fact that patients are under careful monitoring, up to
• Mild OHSS 33% of IVF treatment. results in OHSS .
• Severe OHSS has been reported in 3-8% of IVF cycles.
• Early OHSS : The symptoms usually begin within a week after the egg collection .
• Late OHSS : after a week from egg collection . Late OHSS is more likely to be severe and to last longer .
• Ovarian hyperstimulation syndrome may be classified as mild, moderate or severe by symptoms, signs, biochemistry and blood tests and ultrasound scan findings. The majority of women have a mild or moderate form of the syndrome and invariably resolve within a few days unless pregnancy occurs, that may delay recovery. The worst cases interestingly, tends to be associated with pregnancy.
• Mild OHSS- Patient may complain of pain, a bloated feeling and mild abdominal swelling and nausea. The ovaries are less than 8 cm
• Moderate OHSS- Symptoms of mild OHSS but the swelling and bloating is worse. Abdominal pain and vomiting. Ovarian are usually between 8-12 cm. Fluid may collect in the abdominal cavity (ascitis) causing discomfort.
• Severe OHSS- Symptoms of moderate OHSS but the swelling and bloating is worse. Abdominal pain and vomiting. The patient will feel ill and may suffer from shortness of breath and a reduction in the amount of urine produced. The ovarian size is usually more than 12 cm with large cysts.
Complications associated with severe OHHS include
• Blood clotting disorder.
• Kidney damage
• Respiratory failure.
• Twisted ovaries.
Causes of OHSS
Cause is unknown but it is likely due to the release of chemicals, from the hyperstimulated ovaries. These substances are released into circulation and causes blood vessels to leak fluid into the abdominal cavity, and in severe case into the space around the heart and the lungs . Women at risk of developing OHSS include
• Young (under 30 years) and thin women.
• Women with polycystic ovaries greatly increase the risk.
• High estrogen hormone levels and a large number of follicles .
• Administration of fertility drug.
• The luteal phase, post embryo transfer medication.
Physicians can reduce by
• Monitoring the application of FSH
• by withholding hCG medication.
• OHSS may also be prevented by allowing final follicular maturation, .without hCG administration . This is known as coasting.
TREATMENT OF OHSS
– There is no specific treatment.
– Therapy is based on supportive care until the condition resolve spontaneously. The aim of the treatment is to help relieve symptoms and prevent complications
– Treatment is guided by the severity of OHSS.
– Women with mild and some with moderate OHSS can be managed on an outpatient basis.
– Women with severe and moderate OHSS require admission to the hospital.
The treatment include the following:
• Pain relief with drugs such as paracetamol or codeine. Opiates can be taken if pain is severe, on doctors’ prescription. Non steroidal anti inflammatory drugs should not be used because they may compromise kidney function.
• Antisickness drugs to help reduce sickness and vomiting.
• An intravenous drip for hydration and correction of any electrolyte imbalance
• Support stocking and heparin injection to prevent blood clot in the arms, head, neck, lung ,and legs etc.
• Fluid retained in the abdomen, may be drained , if the abdomen is tense and swollen or there is shortness of breath from severe retention.
• Patient need to continue progesterone luteal support.
This often by varied forms of approach and should follow agreed protocols.
If blood oestrogens and ultrasound scans show a high risk of severe OHSS, hCG should be withheld.
• Egg collection and insemination may occur but any viable embryos should be frozen:
• Fresh embryo transfer should not occur in that cycle but frozen embryo transfer may take place in a subsequent treatment cycle.
• Stop stimulations, and continue with pituitary over ride, until oestrogen levels decline to acceptable values before proceeding to egg collection.
Generally, OHSS does occur when fertility treatment is being applied, and there are remedies to alleviate the problems and complications associated with this condition.
It is pertinent that you see your fertility doctor as soon as you notice any of the symptoms listed above , as a quick intervention reduces the risks of further complications.