Short Communication: FSH Time-Concentration Profiles Before and After Administration of 0.25 mg Cetrorelix in the GnRH-Antagonist Multiple-Dose Protocol for Ovarian Hyperstimulation

Abstract

Purpose : To determine FSH concentration behavior before and after cetrorelix 0.25 mg administration in the GnRHantagonist multiple-dose protocol on day 6 of ovarian stimulation with 150-300 IU daily recombinant FSH. Methods : Blood samples for FSH measurements were drawn from seven women every 15 min from 8 h prior to the first cetrorelix administration in the GnRH-antagonist multiple-dose protocol until 15-32 h thereafter. Results : No significant change of FSH concentration was observed. Conclusions : This observation indicates that no rationale exists of increasing the daily FSH dosage concomitantly to the GnRH-antagonist administration to compensate for a drop of endogenous FSH.

Role of gonadotropin-releasing hormone antagonists in poor responders

“…It is uncertain whether the decline in E 2 levels is exclusively mediated by the pituitary, or if ovarian GnRH receptors also play a role. A recent pharmacologic study found no significant change in serum FSH concentrations after the introduction of 0.25 mg of cetrotide in seven women on stimulation day 6 of 150 -300 IU of recombinant FSH, suggesting that there is no need for supplemental FSH with the introduction of the antagonist (47).…”

Gonadotropin-Releasing Hormone Antagonist in in Vitro Fertilization Superovulation

“…The serum concentration of gonadotropins does not change on initiation of GnRH antagonists [33], therefore increasing the dose of gonadotropins at GnRH antagonist initiation to compensate does not appear to be necessary and does not result in a higher probability of pregnancy [34].…”