Exclusive: Sperm re-transplant offers hope that boys left infertile by chemotherapy could have biological children one day

In a groundbreaking fertility trial, a man whose testicular tissue was frozen before he underwent chemotherapy as a child to be re-transplanted 16 years later has been able to produce sperm.

It is the first time a transplant of cryopreserved prepubertal testicular tissue has been demonstrated to restore sperm production in an adult patient. The 27-year-old man had the sample frozen when he was 10, before undergoing potent chemotherapy as part of treatment for sickle cell disease.

“This is a huge finding,” said Prof Ellen Goossens, of the Vrije Universiteit Brussel, who led the trial. “Many more people will have hope that they can have biological children. It’s great to see for the patients for whom we already have tissue banked.”

Treatments such as chemotherapy and radiotherapy can be life-saving for childhood cancer and sickle cell patients – but can also leave them infertile. After puberty, it is possible to preserve male patients’ sperm to use later in IVF, but this is not an option for prepubescent boys.