Preservation techniques that use low temperatures (cryopreservation) make it possible to store eggs, sperm and embryos for several years, for possible future use.

Cryopreservation of embryos by vitrification

Previously, all the embryos developed during an IVF procedure had to be implanted immediately in the mother’s uterus. The new law makes it possible to implant just one and freeze the others. The Fertas Laboratory in Geneva is equipped to cryopreserve embryos using a process called vitrification. This involves plunging the embryos into liquid nitrogen at -196°C. The temperature drops rapidly and the embryos vitrified almost instantly. Embryos that are preserved in this way can subsequently be transferred into the uterus, without the need to repeat the egg harvesting and fertilization stages.

Cryopreservation of ovocytes by vitrification

The law also allows women to use egg vitrification to preserve their fertility. This technique has long been used for women who need to undergo a complex treatment, such as chemotherapy, which might have a negative impact on their fertility. It has now been extended to healthy women, who simply want to defer their pregnancy.

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Sperm freezing

Men, too, have long frozen their sperm for later use, particularly in the case of treatment that might have a negative impact on their fertility. In some cases, sperm freezing can simplify the technical aspects of IVF.