Effect of GnRH-antagonist, mifepristone and letrozole on preventing ovarian hyperstimulation syndrome in rat model.

RESEARCH QUESTION: Can luteolysis-targeted drugs, gonadotrophin-releasing hormone antagonist (GnRH-ant), mifepristone and letrozole, administered separately or in combination, prevent the progression of ovarian hyperstimulation syndrome (OHSS) in a rat model?

DESIGN

Thirty-six female Wistar rats were randomly divided into six groups, including control group (OHSS group, ovarian hyperstimulation-induced OHSS); GnRH-ant group (OHSS with GnRH-ant treatment); mifepristone group (OHSS with mifepristone treatment); letrozole group (OHSS with letrozole treatment); combination group (OHSS with GnRH-ant, mifepristone and letrozole treatment in combination). The main outcomes were the alterations in OHSS-related indices, including ovarian weight, vascular permeability, serum oestradiol and progesterone levels, corpus luteum proportion and diameter, ovarian vascular endothelial growth factor (VEGF), interleukin 6 (IL-6), caspase-3 and cleaved caspase-3 levels.

RESULTS

No significant difference was found in body weight gain among the six groups. Compared with the control group, the OHSS group showed significant increases in all OHSS-related indices. GnRH-ant treatment showed decreases in vascular permeability, serum oestradiol level, corpus luteum diameter, ovarian VEGF /IL-6 mRNA levels, and increases in ovarian caspase-3 and cleaved caspase-3 levels. Mifepristone treatment demonstrated reduction in serum progesterone level and corpus luteum diameter, and elevation in ovarian caspase-3 and cleaved caspase-3 levels. Letrozole treatment displayed a decline in serum oestradiol level and corpus luteum diameter, and up-regulation in ovarian caspase-3 and cleaved caspase-3 levels. The combination treatment by GnRH-ant, mifepristone and letrozole showed enhanced synergistic effect on reducing OHSS-related indices.

CONCLUSIONS

GnRH-ant, mifepristone and letrozole are beneficial in preventing the progression of OHSS through different luteolytic mechanisms. Cocktail style treatment shows enhanced synergistic effect on preventing the progression of OHSS.