Use of cetrorelix in combination with clomiphene citrate and gonadotrophins: a suitable approach to 'friendly IVF'?Hum Reprod. 2002 Aug; 17(8):2022-6.HR
With the recently introduced GnRH antagonists, soft stimulation protocols on the basis of clomiphene pretreatment should be possible as the pituitary remains fully sensitive at the beginning of the cycle.
A prospective trial was carried out on 107 patients undergoing IVF treatment using the multiple dose GnRH antagonist protocol (cetrorelix), clomiphene citrate, and either HMG (n = 54) or recombinant FSH (rFSH) (n = 53). Different stimulation protocols were used to find the most appropriate one for clinical application.
Both treatment groups, HMG and rFSH, yielded comparable results concerning gonadotrophin dose, stimulation days and pregnancy rate. A mean number of 6.34 +/- 4.4 metaphase II oocytes was retrieved and a mean number of 2.45 +/- 0.65 embryos was transferred. However, the overall rate of premature LH surges was 21.5% (defined as measurement of LH >10 IU/l and progesterone >1 ng/ml) which is unacceptable for clinical practice.
Increasing the daily cetrorelix dose from 0.25 to 0.5 mg might decrease the number of premature LH surges. Soft stimulation protocols with clomiphene should be used cautiously.