Birth following vitrification of a small number of human oocytes

We report the birth of a healthy baby girl at 37 weeks gestation to a 47 ye ar old recipient, after vitrification of mature oocytes from four in-vitro fertilization (IVF) patients. A total of 17 oocytes was vitrified in 1-2 yl of ethylene glycol (40%) and 0.6 mol/l sucrose (20.54%) in open pulled str aws, Eleven oocytes survived after vitrification and five pronuclear zygote s were obtained after intracytoplasmic sperm injection (ICSI), Three embryo s were transferred to three patients, two of whom were the original oocyte donors and pregnancy was not established. The third embryo was donated to a 47 year old infertile woman after preimplantation diagnosis had confirmed euploidy for chromosomes X, 13, 14, 15, 16, 18, 21 and 22. The successfully completed pregnancy is encouraging for further research to explore the pot ential benefits of vitrification for the cryopreservation of human oocytes, given the relatively low success of conventional freezing of human oocytes by slow cooling methods.