Despite encouraging progress in the cryopreservation of oocytes and ovarian tissue, it would certainly be ideal to preserve fertility by effective medicinal ovarian protection under the chemotherapy. The first tests with high-dosed progestins have been replaced by GnRH agonists showing encouraging effects first in animal models and then also in humans. The basis for such a therapy is the fact that in pre-adolescent girls, the ovaries sustain much less damage by chemotherapy. Since quiescent ovaries, i.e. ovaries without FSH stimulation, are less receptive for toxic chemotherapies, the secretion of FSH in post-adolescent women is inhibited using GnRH agonists.

However, even that the effectiveness of this therapy has not been conclusively proven, the first metananlyses indicate some protective effect (Bedaiwy et al., Fertil Steril 2011).

Nevertheless, in view of the above data on the effectiveness of GnRH agonists as ovarian protection agents, this medication can be prescribed to women undergoing chemotherapy, especially if there is no alternative fertility protection method available. However, unclear data and the “off label use” must be discussed with the patient. Furthermore, GnRH agonists should be prescribed only after the patient is informed thoroughly about the complete range of preventive concepts by an experienced FertiPROTEKT centre (contacts) in order to guarantee in-depth knowledge about alternative treatment options. For example, GnRH can be combined with other techniques such as the cryopreservation of unfertilised and fertilised oocytes and the cryopreservation of ovarian tissue.

If GnRH agonists are taken during chemotherapy, they should ideally be administered 1 week before the chemotherapy starts since the initial FSH release (flare-up) leads to undesired ovarian stimulation. If the time window until the onset of chemotherapy is shorter than one week, it is possible either to combine the GnRH agonists with GnRH antagonists to reduce the flare-up or to apply the first dose of GnRH agonist only 1-2 weeks after the first cycle of chemotherapy.

We recommend depot preparations to be applied monthly or quarterly whose suppressing effect should last 1-2 weeks longer than the last chemotherapy.