Fixed versus flexible gonadotropin-releasing hormone antagonist administration in in vitro fertilization: a randomized controlled trial.Fertil Steril. 2011 Feb; 95(2):558-62.FS
To evaluate whether the incidence of luteinizing hormone (LH) rise is reduced by using a flexible compared with a fixed day-6 protocol of GnRH antagonist administration.
Randomized controlled trial.
Tertiary university hospital.
Patients undergoing in vitro fertilization (n = 146).
Ovarian stimulation was performed using recombinant FSH and GnRH antagonists. GnRH antagonist cetrorelix (0.25 mg/d) was started either on day 6 of stimulation (fixed group) or when LH was >10 IU/L, and/or a follicle with mean diameter >12 mm was present, and/or serum E(2) was >150 pg/mL. Patient monitoring was initiated on day 3 of stimulation.
MAIN OUTCOME MEASURE(S)
Incidence of LH rise.
No statistically significant difference was observed between the flexible and fixed groups regarding the incidence of LH rise, which was lower in the flexible group (11.0% vs. 15.1%, difference -4.1%, 95% confidence interval -15.4% to +7.1%). No LH surges were observed in any of the patients studied.
Flexible antagonist administration from day 3 onward does not appear to reduce the incidence of LH rises compared with fixed antagonist administration on day 6 of stimulation.