In new research, scientists removed stem cells and cultured sperm in the laboratory in a breakthrough that could lead to new treatments and drugs for men currently unable to have children. The development raises hopes that young boys undergoing chemotherapy for testicular cancer will still be able to father their own children when they grow up.

The sperm was produced in a test-tube from the cells taken from a newborn mouse testicles and then injected into eggs to produce to twelve healthy babies, four male and eight female, which were all fertile and able to reproduce themselves in adulthood.

Dr Takehiko Ogawa, an urologist at Yokohama City University in Japan, said the production of sperm in the testes is one of the most complex processes in the body. It has never been reproduced in a test tube in mammals before. They achieved the feat by providing most of the cellular components found in the testicles in a dish and watched as the stem cells grew into sperm cells. They then used IVF (in vitro fertilization) techniques to produce male and female offspring that were themselves fertile.

The researchers, whose findings are published in Nature, said: "The obtained sperm resulted in healthy and reproductively competent offspring."

The testes tissue was still worked after being frozen in liquid nitrogen and could still be used several weeks later – suggesting it may be possible in humans to produce their own biological offspring years later.

"In men, this problem can be mitigated by banking sperm before treatment. The solution is less straightforward in prepubescent boys.

"In this scheme, boys would undergo testicular biopsy before chemotherapy or radiation therapy, to obtain tissue for cryopreservation (freezing).

If infertility occurs, the testicular fragments could be thawed and sperm obtained from organ culture for IVF. This could help discover new drugs or treatments to stimulate infertile men to produce more or better sperm. It also may help preserve the fertility of some males.