Overview
Ovarian hyperstimulation syndrome (OHSS) is a complication seen in some forms of infertility treatment. It is postulated that the presence of multiple luteinized cysts within the ovaries results in high levels of not only oestrogens and progesterone but also vasoactive substances such as vascular endothelial growth factor (VEGF). This results in increased membrane permeability and loss of fluid from the intravascular compartment
Whilst it is rarely seen with clomifene therapy is more likely to be seen following gonadotropin or hCG treatment. Up to one third of women who are having IVF may experience a mild form of OHSS
The RCOG uses the following classification of OHSS
| Mild | Moderate | Severe | Critical |
|---|---|---|---|
| • Abdominal pain | |||
| • Abdominal bloating | • As for mild | ||
| • Nausea and vomiting | |||
| • Ultrasound evidence of ascites | • As for moderate | ||
| • Clinical evidence of ascites | |||
| • Oliguria | |||
| • Haematocrit > 45% | |||
| • Hypoproteinaemia | • As for severe | ||
| • Thromboembolism | |||
| • Acute respiratory distress syndrome | |||
| • Anuria | |||
| • Tense ascites |