12.06.2024

A team at the University Hospital Bonn (UKB) has established a modern method for the cryopreservation of ovarian tissue known as vitrification. This technique is used to preserve fertility before cancer therapies.

For the first time in Europe, a successful birth was reported following the retransplantation of flash-frozen, stored and thawed ovarian tissue. The results of this study were published in the journal Reproductive BioMedicine.

Image: Laboratory procedure for the cryopreservation of ovarian tissue; Copyright: Alessandro Winkler University Hospital Bonn (UKB)

For the first time in Europe, the team led by Prof. Nicole Sänger from the UKB reports a successful delivery after retransplantation of flash-frozen, stored and thawed ovarian tissue.

Products and exhibitors related to this topic

Exhibitors and products related to this topic can be found in the database of MEDICA:

Background to cryopreservation

A woman's oocyte reserve is limited. Gonad-damaging therapies such as chemotherapy can lead to infertility. One way of preserving fertility is the cryopreservation of ovarian tissue. A part of the ovary is removed and frozen before gonadotoxic therapy. At a later date, this tissue can be thawed and reimplanted in order to return undamaged egg cells to the body.

Since 2004, numerous international research groups have achieved successful pregnancies after cryopreservation, thawing and retransplantation of ovarian tissue. "This illustrates the high potential of this method, which is mainly based on the cryopreservation procedure of slow freezing," says Dr. Andreas Schallmoser, Head of the Reproductive Medicine Laboratory at the UKB.

Advantages of vitrification

Vitrification, a flash freezing process, offers significant advantages over slow freezing. When the temperature is gradually lowered to -196°C, the formation of ice crystals cannot be completely avoided, which can compromise the integrity of the tissue. With vitrification, on the other hand, the tissue is frozen within fractions of a second. "This is because the formation of ice crystals is not possible - the sample vitrifies, so to speak," explains Dr. Rebekka Einenkel, Head of the Gynecological Endocrinology and Reproductive Medicine Research Laboratory at the UKB

Breakthrough in research

In earlier studies by the team led by Prof. Nicole Sänger, Director of the Department of Reproductive Medicine at the UKB, Dr. Schallmoser and Dr. Einenkel were able to demonstrate the positive influence of vitrification on the vitality of the egg cells and their environment as well as the release of vasculogenic substances. These substances are essential for successful retransplantation.

"The first birth in Europe after vitrification, thawing and retransplantation of ovarian tissue is a milestone for our patients and our center. Thanks to our research focus on vitrification and thawing of human tissue and cells, we can offer fertility treatments at the highest level," says Prof. Sänger from the Department of Reproductive Medicine at the UKB.

MEDICA-tradefair.com; Source: University Hospital Bonn (UKB)

More about the UKB at: www.ukbonn.de/en