ABSTRACT
OHSS occurs after overstimulated ovaries have been exposed to hCG. The condition therefore results most commonly when sensitive (usually polycystic) ovaries are exposed to excessive quantities of FSH and then to hCG. That severe OHSS is often associated with pregnancy is probably related to the persistence of hCG in this situation. Even when the ovaries have been severely overstimulated, OHSS can be prevented by avoiding exposure of the ovaries to LH and/or hCG.
