"This is proof of principle in humans."
— Professor Rod Mitchell, University of Edinburgh
A 27-year-old man has become the first person in the world to produce sperm after receiving a transplant of testicular tissue that was preserved before he underwent chemotherapy at age 10.
Sixteen years after his testicular tissue was frozen, surgeons grafted it back into his body. One year later, the grafts contained mature sperm, which were successfully collected and frozen.
The breakthrough, led by Professor Ellen Goossens at Vrije Universiteit Brussel, offers new hope for thousands of boys who face infertility due to cancer treatments.
The Procedure
The man’s tissue was originally banked in 2002, before he received chemotherapy for sickle cell disease. At the time of transplant, surgeons placed:
- Four tissue fragments into his remaining testicle
- Four fragments under the skin of his scrotum
After one year, two grafts from inside the testicle were found to contain mature sperm. These were collected and frozen for future use.
The sperm are not expected to appear naturally in semen, because the grafts are not connected to the sperm duct. However, they can be used for in vitro fertilization (IVF).
Why This Matters
Chemotherapy and radiotherapy can cause permanent infertility in children. After puberty, sperm can be banked. For prepubertal boys, however, no sperm is available to freeze.
The Belgian clinic began banking testicular tissue from prepubertal patients in 2002. Similar programs now exist worldwide:
- UK: Over 1,000 patients have banked tissue
- Globally: Over 3,000 patients have banked tissue
- Estimated UK need: Around 200 patients per year could benefit
What's Next
Professor Ellen Goossens stated that the finding provides hope for many patients, though the ability of the sperm to fertilize an egg remains to be tested.
Professor Rod Mitchell of the University of Edinburgh called the result "proof of principle in humans." His clinic expects to carry out its first transplants soon.
The first patient is now considering a second round of grafts or proceeding directly with IVF using the frozen sperm.