Contraceptive treatment before gonadotrophin-releasing hormone agonist administration presents advantages in women with a tendency to hyper-response and simplifies donor–recipient treatment synchronization. This study compares response to gonadotrophin stimulation under hypophyseal suppression in oocyte donors with or without vaginal contraceptive pretreatment. METHODS: One hundred and ninety oocyte donors were recruited in a single centre and prospectively assigned to one of two treatment groups, according to the day of the week menstruation initiated: Group VC–, no prior vaginal contraceptive and Group VC+, prior vaginal contraceptive. RESULTS: VC+ patients presented a significantly higher cancellation rate, lower plasma estradiol levels and fewer follicles >12 mm on the day of hCG, versus the VC– group. Number of oocytes recovered was significantly lower in the VC+ group. All the cases of severe ovarian hyperstimulation syndrome (SOHSS) were in the VC– group. Pregnancy rates by embryo transfer to synchronic recipients were similar between VC+ and VC– (59.5 versus 57.9%, respectively). CONCLUSIONS: Vaginal contraceptive pretreatment resulted in a higher ovarian suppression, whereas SOHSS rate was lower than in donors who did not receive pretreatment. There were no differences in pregnancy rates between the two groups of synchronic oocyte recipients.