[The programming of IVF cycles with antagonists].

Modern gonadotrophin-releasing hormone (GnRH) antagonists such as cetrorelix and ganirelix reliably prevent premature LH surge in controlled ovarian hyperstimulation for assisted reproductive technologies. Nevertheless, GnRH antagonists do not allow homogenization of the follicle cohort, as observed with GnRH agonists. Administration of estrogens, progestogens or contraceptive pill in previous late luteal phase, may improve the size homogeneity of antral follicles. The coordination of follicular development may optimize ovarian response to r-FSH/GnRH antagonist protocols.