Triploid pregnancy after ICSI of frozen testicular spermatozoa into cryopreserved human oocytes.

Although freezing oocytes is ethically more acceptable than cryopreservation of embryos, variable oocyte survival, fertilization rate and possible risk of increased ploidy after cryopreservation have precluded the widespread clinical application of oocyte cryopreservation in assisted reproduction techniques. We report a triploid pregnancy from intracytoplasmic sperm injection of recombinant FSH-stimulated frozen/thawed testicular spermatozoa into cryopreserved oocytes in a hormone replacement cycle. To our knowledge, this is the first report of a pregnancy where both gametes have been frozen. It illustrates the need for further research when applying new techniques in assisted reproduction.