Ovarian hyperstimulation complicating the clinical presentation of a pre-existing ectopic pregnancy.

A 32-year-old nulliparous woman underwent hMG induction of superovulation, started on the third day of "menses." The presence of hyperstimulation confused the clinical picture of ectopic pregnancy conceived during the previous cycle. This case illustrates that (1) the clinical findings of hyperstimulation may mask those of ectopic pregnancy; (2) the ovary is not refractory to hMG in the presence of circulating hCG; and (3) an inappropriately high beta-hCG value is suggestive of gestation initiated during a previous cycle.