Live birth from a zygote cryopreserved for 8 years.

After a cryopreservation period of 8 years, four zygotes were thawed and transferred to the patient's uterine cavity. A singleton pregnancy resulted in the delivery of a normal male. This case report offers evidence that long terms of cryopreservation are consistent with full developmental potential post-thaw, and encourages further examination of imposing limits on length of storage of frozen concepti.