Ovarian hyperstimulation syndrome (OHSS) is a complication arising from iatrogenic induction of ovulation, characterized by an exaggerated response to hormonal therapies used in procedures such as in-vitro fertilization (IVF).

Aetiology

OHSS occurs due to an excessive response to hormones used in IVF, leading to multiple follicles maturing and enlarging. Upon ovulation, each of these follicles transforms into a corpus luteum, resulting in an overproduction of oestrogen, progesterone, and local cytokines, especially vascular endothelial growth factor (VEGF).

PC

The overstimulation of the ovaries can cause significant enlargement, leading to pressure on surrounding structures. This can result in the following symptoms:

• Bloating
• Abdominal discomfort

VEGF can cause blood vessels to leak, leading to fluid retention manifesting as:

• Oedema
• Pleural effusions
• Ascites
• Weight gain

Investigations

The following investigations are often conducted to diagnose OHSS and assess the severity:

• Routine blood tests: These are used to evaluate haemoconcentration and detect potential organ dysfunction.
• Chest X-ray: This is performed to identify the presence of pleural effusion.