Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of the luteal phase and/or early pregnancy after ovulation induction (provoking ovulation in anovulatory women) or of ovarian stimulation (in the context of intrauterine insemination or in vitro fertilisation).
The essence of the OHSS is cystic enlargement of the ovaries
and a fluid shift from the intravascular to the third space due
to increased capillary permeability and ovarian neoangiogenesis. Its occurrence is dependent on the
administration of human chorionic gonadotropin (hCG).
OHSS is extremely rare without hCG adminitration. Its
impact on the general health of the patient can be very
deleterious and fatal cases have occasionally been reported.
