Successful use of human semen cryobanking for in vitro fertilization.

Frozen-thawed donor semen was compared with freshly ejaculated donor semen for in vitro fertilization of human oocytes in patients with infertile husbands. There was no significant difference in the fertilization rates between frozen-thawed (85%) and fresh spermatozoa (78%). Fertilization occurred with semen stored for as long as 27 months and with numbers of spermatozoa as low as 20,000/ml culture medium for insemination of oocytes. Pregnancy rates of embryos, fertilized with frozen-thawed and freshly ejaculated spermatozoa, were similar following embryo transfer.