Abstract: Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic side effect associated with assisted reproductive technology. The disorder is defined by enlargement of cysts in the ovaries, as well as fluid movement from the intravascular space to the third space due to an increase in capillary permeability as well as ovarian neoangiogenesis. The cause of the condition is being treated with human gonadotrophin chorionic (hCG). OHSS is very rare without the use of hCG. Its effect on the overall wellbeing of patients may be extremely detrimental and even tragic cases have been documented. The link with hCG OHSS is believed to be controlled by an increase in the expression of the angiogenic molecules VEGF.