GnRH antagonist versus long GnRH agonist protocol in poor responders undergoing IVF: a randomized controlled trial.
BACKGROUND
This is the first published report of a prospective, randomized, controlled trial comparing a fixed, multi-dose GnRH antagonist protocol with a long GnRH agonist protocol in poor responders undergoing IVF.


METHODS
Sixty-six poor responders were randomized into two groups: the study group received 0.25 mg of cetrorelix daily starting on day 6 of stimulation; the control group received 600 microg of buserelin acetate daily starting in the mid-luteal phase of the preceding cycle. Both groups were given a fixed dose of recombinant FSH (300 IU daily) for stimulation.


RESULTS
There were no significant differences in the cycle cancellation rates, duration of stimulation, consumption of gonadotrophins, and mean numbers of mature follicles, oocytes and embryos obtained. The implantation rates were similar, but the number of embryos transferred was significantly higher for the antagonist group (2.32 +/- 0.58 versus 1.50 +/- 0.83; P = 0.01). The pregnancy rates were also higher in the antagonist group, but the difference was not statistically significant.


CONCLUSIONS
A fixed multi-dose GnRH antagonist protocol is feasible for patients who are poor responders on a long agonist protocol; however, our study failed to demonstrate an overall improvement in ovarian responsiveness. Clinical outcomes may be improved by developing more flexible antagonist regimens, an approach that requires further evaluation.
Cheung
Lai-Ping
LP
Department of Obstetrics and Gynecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China. lpcheung@cuhk.edu.hk
Lam
Po-Mui
PM
Lok
Ingrid Hung
IH
Chiu
Tony Tak-Yu
TT
Yeung
Sum-Yee
SY
Tjer
Ching-Ching
CC
Haines
Christopher John
CJ
D000328:Adult; D002064:Buserelin / Q000008:administration & dosage* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004624:Embryo Transfer / Q000706:statistics & numerical data; D005240:Feasibility Studies; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage* / Q000627:therapeutic use; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage* / Q000819:agonists* / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000627:therapeutic use; D006727:Hormone Antagonists / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D011994:Recombinant Proteins / Q000627:therapeutic use; D017211:Treatment Failure
D005300:Fertility Agents, Female; D006727:Hormone Antagonists; D011994:Recombinant Proteins; D007987:Gonadotropin-Releasing Hormone; D005640:Follicle Stimulating Hormone; C062876:cetrorelix; D002064:Buserelin