A prospective randomized feasibility study was carried out on 10 patients undergoing IVF treatment using a single-dose LHRH antagonist protocol (cetrorelix, Cetrotide) with clomiphene citrate in combination with either human menopausal gonadotrophin (HMG) (n = 5) or recombinant human FSH (rFSH) (n = 5). Both treatment-groups, HMG and rFSH, were comparable with regard to age (33.2 +/- 2.6 versus 34.4 +/- 4.0 years) BMI (23.2 +/- 2.6 versus 22.7 +/- 1.6) and cause of infertility. They yielded comparable results concerning gonadotrophin dose (19.8 +/- 8.7 versus 17.0 +/- 8.9), stimulation days (6.5 +/- 2.0 versus 5.8 +/- 1.9) and live births (one versus two). No premature LH surge (LH >10 IU/ml and progesterone >1 ng/ml) occurred. The overall baby take-home rate was 30%. In a small number of patients, cetrorelix could be shown to effectively prevent premature LH surges in stimulation protocols combining clomiphene with gonadotrophins with an excellent baby take-home rate per started cycle of 30%.