Life after the deep freeze

Organ transplantation is limited by the availability of fresh donor organs, and would benefit if organs could survive freezing. Early cryopreservation experiments had encouraging results but never realized their potential. In January 24 Nature, Xiang Wang and colleagues from Centre Hospitalier de l'Université de Montréal, Canada, show that pregnancy it is possible after transplantation of cryopreserved ovaries.

Wang et al. transplanted into rats ovaries, fallopian tubes and the upper segment of the uterus en bloc following overnight storage in liquid nitrogen. They found that four animals with cryopreserved grafts (57%) had follicular ovaries, and their corpora lutea indicated recent ovulation. In addition, one animal was pregnant, with two healthy fetuses implanted on either side of the uterine anastomosis (Nature 2002, 415:385).

"Our success with ovarian transplants should stimulate investigation into the improvement of cryopreservation techniques for other organs", concluded the authors.