Is the flexible GnRH antagonist protocol better suited for fresh eSET cycles?
OBJECTIVE
This study was performed to evaluate the efficacy of the flexible GnRH antagonist protocol in comparison with the long GnRH agonist protocol in elective single embryo transfer (eSET) practice. It was conducted in a publicly funded in vitro fertilization program.


METHODS
We performed a prospective cohort analysis of data from a private infertility clinic from August 2010 to August 2011. Three hundred fourteen women with normal ovarian reserve and undergoing fresh eSET cycles were included. Sixty-four women underwent follicular stimulation using a flexible GnRH antagonist protocol, and 250 underwent stimulation with a standard long mid-luteal GnRH agonist protocol.


RESULTS
Implantation rates (35.9% in the GnRH antagonist group and 29.6% in the GnRH agonist group, P = 0.5) and ongoing pregnancy rates (32.8% in the GnRH antagonist group and 28.8% in the GnRH agonist group, P = 0.5) were equivalent in both groups. The duration of stimulation (9.8 ± 2 days vs. 10.7 ± 1.8 days, P < 0.001) and total FSH dose required (2044 vs. 2775 IU, P < 0.001) were lower in the GnRH antagonist group than in the GnRH agonist group. The number of mature oocytes (6.0 vs. 10.0, P < 0. 001) and number of embryos (5.0 vs. 7.0, P < 0.001) were also lower in GnRH antagonist group. However, the number of embryos cryopreserved was similar in both groups (median 2.0, P = 0.3).


CONCLUSIONS
In women undergoing in vitro fertilization, the flexible GnRH antagonist protocol yields implantation and ongoing pregnancy rates that are similar to the long GnRH agonist protocol, and requires lower doses of gonadotropins and a shorter duration of treatment. The flexible GnRH antagonist protocol appears to be the protocol of choice for an eSET IVF program.
PROCREA Clinics, Montreal QC; ART-PGD Centre, CHU Sainte-Justine, Montreal QC; Department of Obstetrics and Gynecology, University of Montreal, Montreal QC.
Elias M
EM
Dahdouh
PROCREA Clinics, Montreal QC.
Francisco L A F
FL
Gomes
PROCREA Clinics, Montreal QC; ART-PGD Centre, CHU Sainte-Justine, Montreal QC; Department of Obstetrics and Gynecology, University of Montreal, Montreal QC.
Louis
L
Granger
PROCREA Clinics, Montreal QC; Department of Obstetrics and Gynecology, University of Sherbrooke, Sherbrooke QC.
Belina
B
Carranza-Mamane
PROCREA Clinics, Montreal QC.
Faez
F
Faruqi
PROCREA Clinics, Montreal QC.
Tiao-Virirak
TV
Kattygnarath
PROCREA Clinics, Montreal QC.
Pierre
P
St-Michel
D000328:Adult; D015331:Cohort Studies; D010064:Embryo Implantation / Q000187:drug effects*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists / Q000037:antagonists & inhibitors*; D006727:Hormone Antagonists / Q000008:administration & dosage*; D006801:Humans; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D011446:Prospective Studies; D056826:Single Embryo Transfer / Q000379:methods*
D006727:Hormone Antagonists; D007987:Gonadotropin-Releasing Hormone
GnRH antagonist; eSET; elective single embryo transfer; long GnRH agonist protocol; ovarian stimulation