Exposure to high levels of luteinizing hormone and estradiol in the early follicular phase of gonadotropin-releasing hormone antagonist cycles is associated with a reduced chance of pregnancy.
OBJECTIVE
To compare ongoing implantation rates under two different GnRH antagonist protocols.


METHODS
Randomized controlled trial.


METHODS
Tertiary referral center.


METHODS
One hundred eleven women undergoing ovarian stimulation for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).


METHODS
Ovarian stimulation with 150 IU recombinant-FSH (rec-FSH) starting on day 2 of the cycle and GnRH antagonist starting either on day 6 of stimulation (fixed group) or when a follicle of > or = 15 mm was present after at least 5 days of stimulation (flexible group). In the flexible group, the rec-FSH dose was increased to 250 IU when the antagonist was initiated.


METHODS
Ongoing implantation and pregnancy rate.


RESULTS
In patients with no follicle of > or = 15 mm present on day 6 of stimulation, a significantly lower ongoing implantation rate was observed if the flexible scheme was applied as compared with the fixed scheme of administration (8.8% vs. 23.9%, respectively). Exposure of the genital tract to LH or E2 from initiation of stimulation to antagonist administration was able to distinguish between pregnant and nonpregnant patients in the population studied.


CONCLUSIONS
High exposure of the genital tract to LH and E2 in the early follicular phase is associated with a reduced chance of pregnancy in cycles stimulated with recombinant FSH and GnRH antagonist for IVF/ICSI.
Kolibianakis
Efstratios M
EM
Centre for Reproductive Medicine, Dutch-Speaking Brussels Free University, Brussels, Belgium. stratis@easynet.be
Albano
Carola
C
Kahn
Jarl
J
Camus
Michel
M
Tournaye
Herman
H
Van Steirteghem
Andre C
AC
Devroey
Paul
P
D000328:Adult; D004334:Drug Administration Schedule; D010064:Embryo Implantation / Q000187:drug effects*; D004624:Embryo Transfer; D004958:Estradiol / Q000097:blood / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D005498:Follicular Phase / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood / Q000502:physiology*; D008297:Male; D006080:Ovarian Follicle / Q000378:metabolism / Q000502:physiology; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D018709:Statistics, Nonparametric
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C061018:ganirelix