Flexible GnRH antagonist versus flare-up GnRH agonist protocol in poor responders treated by IVF: a randomized controlled trial.

Background: Although initial studies in poor responders using GnRH antagonists have reported encouraging results, they are limited in number, only a few of them are prospective, while the majority is characterized by limited power to detect a clinically important difference.

Methods: A randomized controlled trial was performed in patients with one or more previous failed IVF cycles in which five or less oocytes were retrieved, using > or =300 IU of gonadotrophins/day. Patients were randomized by computer-generated list and treated by either the flare-up GnRH agonist protocol (n = 90) or a flexible GnRH antagonist protocol (n = 180).

In a flexible antagonist protocol, earlier, criteria-based initiation of GnRH antagonist is associated with increased pregnancy rates in IVF.

Background: The purpose of the study was to assess ongoing pregnancy rates across groups of patients treated by IVF, which were defined according to criteria aimed at the prevention of premature LH surge and used for initiating GnRH antagonist.

Methods: This is a prospective observational cohort study. During the last 3 years, in IVF-ICSI patients undergoing controlled ovarian stimulation (COS) with the antagonist protocol, the antagonist administration was initiated according to at least one of the following patient-specific criteria: (i) at least one follicle measuring >14 mm; (ii) estradiol levels >600 pg/ml; and (iii) LH levels >10 IU/l.