Researchers say the birth represents a new world record for the longest period of cryopreservation, or freezing of sperm, to result in a live birth.
The healthy baby boy was born two years ago to a couple in the U.K. more than 21 years after the father was successfully treated for testicular cancer with surgery, radiation, and chemotherapy between 1979 and 1981.
The couple, speaking anonymously, say they wanted their case to be reported as an example of the safety and effectiveness of long-term sperm freezing. They also wanted to encourage young cancer patients to think positively about their future at a time in which they are under emotional stress due to their condition and impending treatment.
New Record for Sperm Preservation
A report of the birth appears in the June issue of Human Reproduction.
Researchers say the male testicular cancer patient froze five samples of sperm before undergoing treatment, which was to leave him sterile. The sperm was stored until he married and wished to have a family.
"Even after 21 years of storage, the percentage of [active] sperm after thawing was high," says researcher Greg Horne, a senior embryologist at St. Mary's Hospital, in a news release.
ICSI, or intracytoplasmic sperm injection, the in vitro fertilization (IVF) technique that involves a single sperm being injected into an egg, was used to fertilize his partner's eggs, and the baby was born in 2002 after the fourth attempt.
"This case report provides evidence that long-term freezing can successfully preserve sperm quality and fertility," says Horne. "This is important to know because semen stored by young cancer patients is undertaken at a time of great emotional stress when future fertility is unlikely to be an immediate priority."
"It also suggests that we need to extend follow-up studies of cryobanked sperm up to 25 years at least," says Horne. "A recent study showed that only 27% of men who stored semen at our center prior to cancer treatment used their samples within 10 years, and in the [United Kingdom] regulations allow sperm to be stored until a man is 55."
In the United States, sperm can be stored indefinitely. Check with individual cryobanks about their sperm storage policies.
SOURCES: Horne, G. Human Reproduction, June 2004; vol 19: pp 1448-1449. News release, European Society for Human Reproduction and Embryology.