New protocol for commencing the GnRH antagonist in assisted conception treatment cycles: elimination of the premature LH surge with similar pregnancy rates.

GnRH antagonists have been used with increasing frequency in assisted reproduction treatments over the past few years and have been associated with quicker and more profound LH suppression and shorter treatment cycles than conventional GnRH agonists. Usually, these are commenced on day 6 of FSH stimulation without allowing for patient variation in response to treatment. The study was aimed at individualising this protocol to the patients' ovarian response. The control group included 215 treatment cycles where the GnRH antagonist was commenced on day 6 of FSH stimulation. A new individualised protocol was formulated, applied to practice and 172 treatment cycles following that were analysed. The study group had no premature LH surges (LH > 10 iu x mL(-1)) compared to the control group who had a rate of 4.1%. There was also a higher fertilisation and clinical pregnancy rate in the study group (P = 0.06). It is concluded that the new individualised GnRH antagonist protocol eliminates premature LH surges in assisted conception treatment cycles and may improve clinical pregnancy rates compared to the conventional protocol of "day 6 commencement".