When in the course of IVF treatment more oocytes have been fertilized than will be transferred back to the uterus (usually 2-3 embryos), the remaining embryos may be frozen with the couple's written consent and kept for ten years maximum for further embryo transfers.

After the expiration of this period, any remaining embryos must be destroyed in accordance with the Reproductive Medicine Law of 1992 (FMedG92) and the Reproductive Medicine Amendment 2004 (FMedG92).
The frozen embryo cycles may be carried out in natural cycle or it may be recommended that the women receive a course of harmonic replacement. The procedure is tried and proven; it is safe but results in a lower pregnancy rate.