GnRH analogs: depot versus short formulations

Gonadotropin releasing hormone agonists (GnRH-a) are widely used in controlled ovarian hyperstimulation (COH) for assisted reproduction (ART). Two different formulations are now available: short formulations and depot formulation. Some authors have suggested that depot GnRH-a induce a too high pituitary suppression and have put forward protocols using reduced GnRH-a doses. A reduced dose of daily triptorelin is enough for pituitary suppression during ovarian stimulation but provides no significant improvement in IVF cycle outcome when compared with depot formulation in normally responding women. However, it seems to improve ovarian response and overall results in poor responding patients. Low doses of short GnRH-a allow shorter treatment, requiring lower amounts of gonadotropins. This possibility should be considered in view of its economic advantage.