Controlled ovarian hyperstimulation--an inflammatory state.

OBJECTIVE: Controlled ovarian hyperstimulation (COH) is apparently a key factor in the success of in vitro fertilization-embryo transfer. One of the major complications of COH is severe ovarian hyperstimulation syndrome (OHSS), which may be attributable to a massive increase in systemic inflammatory cytokines or to neutrophil activation. The aim of the present review was to investigate the role of COH in the induction of an inflammatory response.
METHODS: Major studies that have reported on the association between COH and inflammation were identified through MEDLINE searches and the published literature.
RESULTS: Several inflammatory mediators, namely, C-reactive protein and leukocyte and endothelial selectins, showed a significant increase after human chorionic gonadotropin (hCG) administration in vivo, reflecting an inflammatory state, and neutrophil and endothelial activation, respectively. On the other hand, hCG showed a direct depressive effect on mononuclear cells in vitro. Because the development of OHSS almost always follows hCG administration, the negative effect of hCG on peripheral mononuclear cells indicates that it probably causes OHSS by an indirect mechanism.
CONCLUSION: We suspect that hCG stimulates the ovaries to produce and secrete a still unknown intermediate factor, which in turn activates inflammatory processes that may lead to an increase in capillary permeability.