Can the galenic form of GnRH agonist used during long IVF protocole vary the pregnancy rate?

Luteal defect is common during IVF cycles using GnRH agonist, It could be interesting to make up for this problem by using short acting GnRH agonist (effective for 24 hours), more handy at the end of the stimulation. 160 patients included in a long IVF protocol at the Bordeaux CHRU FIV center have been randomized, from September 1993 to August 1994, for the analog's choice (long or short) at the beginning of the stimulation. The stimulation's parameters, the hormonal dosages and the pregnancy rate are independant of the galenic form used. In close, the use of long-acting GnRH analog (sympler to use) sems preferable.