RELATIONSHIP OF TIMING OF AGONIST ADMINISTRATION IN THE CYCLE PHASE TO THE OVARIAN RESPONSE TO GONADOTROPINS IN THE LONG DOWN-REGULATION PROTOCOLS FOR ASSISTED REPRODUCTIVE TECHNOLOGIES

Objective: To assess whether the ovarian response to exogenous gonadot ropins and cycle performance is affected by different timing of an ago nist administration in long down-regulation protocols. Design: An agon ist was administered irrespective of cycle phase, with exogenous gonad otropin beginning 15 days later. Patients: Five hundred fifty-seven no rmovulatory infertile patients, aged less than or equal to 38 years, w ere classified into seven study groups, depending on the phase of the cycle in which agonist was started. Main Outcome Measures: Endocrine p rofile, amount of exogenous stimulation, occurrence of ovarian cysts, mean number of oocytes recovered and embryos transferred, pregnancy ra te, implantation rate, and live-birth rate of the seven groups. Result s: The ovarian response of the groups did not show any statistically s ignificant differences in relation to the initiation of the agonist. T he only effect was a different incidence of ovarian cyst formation, bu t this phenomenon did not affect cycle performance. The pregnancy, imp lantation, and live-birth rates showed differences that did not reach statistical, significance. Conclusion: Agonists initiation can be prog rammed in advance irrespective of the phase of the cycle. This approac h can be of help for the logistics of assisted reproduction programs.