The world record for a birth from frozen sperm has risen to 40 years, a Minneapolis company claims. Reprotech, which specialises in cryopreservation of sperm, eggs and embryos, says that the sperm was donated by a Japanese-American in 1971. He and his wife could not have children but he wanted his blood line to continue, so he stored his sperm with a sperm bank. Twin girls were born recently to a couple who needed donor sperm and were intrigued by the donor’s story.

The participants in this story are all anonymous, so it is difficult to get more information. However, it seems that the frozen sperm had been stored with different companies and in at least four different locations over four decades. A spokesman for Reprotech said that the donor had probably spent more than US$8,000 to keep his sperm frozen.

The donor did want a role in selecting the couple, but he does not want to participate in the children’s lives. Rene Almeling, a sociologist at Yale University who is an expert on the medical market for sperm, said that the time gap raised interesting issues. "The fact that the donor might be long dead when the children are living cuts off a potential avenue of connection between donor and offspring -- an avenue that many more are choosing to pursue these days," she told St Paul Pioneer Press.

A spokesman for Reprotech said that it is impossible to say how long sperm can be stored, but several thousand years is not impossible.