baby born from sperm
...imit The baby boy was born in 2002 after his father and mother had undergone in-vitro fertilisation. The frozen sperm was thawed and inserted into eggs to create the embryos used. Barratt says the success is no surprise as frozen animal sperm has been thawed and used successfully up to 40 years after it was first stored. He says theoretically there is no time limit for using frozen human sperm, as the sperm simply stays inert in the freezer. Previously, researchers had been concerned that keeping sperm frozen for very long periods could cause damage. One worry was that it would be exposed to more background radiation than sperm freshly created in the body. Frozen sperm are suspended in an inert state, so they cannot repair any DNA damage that occurs. However, the rate of background radiation is now considered to be so low that any damage would be negligible, he says. Barratt points out that there may even be some benefits of long-term storage, because as a man ages there is a decline in the quality of his sperm. "In many ways this [technique] is an advantage - the baby born has the sperm DNA of a 20-year-old rather than a 40-year-old," he says. Ban cloning babies, demand world's top scientists Cloning babies should be banned worldwide by the United Nations, more than 60 of the world's leading scientific academies demanded on Monday. "Human reproductive cloning is unsafe, and no responsible scientist would attempt it given the huge health risks that are involved," said Yves Quéré of the InterAcademy Panel on International Issues, which launched the joint declaration in Trieste, Italy on behalf of the 63 academies. But the ban should not extend to therapeutic cloning - the creation of cloned cells which could form tissue for transplant into diseased or injured patients - they added. Speaking at a simultaneous conference in London, Robert May, president of the UK's leading scientific academy, the Royal Society, stressed that therapeutic cloning held such great medical promise that individual countries should be allowed to decide for themselves whether or not to introduce a ban. The issue will be hotly debated in New York next week when the UN's legal committee meets to discuss a draft convention tabled by Costa Rica for a global ban both on reproductive and on therapeutic cloning. Tissue of choice Already, the UN has made two failed attempts at a treaty. Almost every delegation wants a ban on cloned babies, but some countries including the US, the Vatican and other Roman Catholic countries have held out for a ban on therapeutic cloning too. The practice is controversial because in humans, the first step would be to grow an embryo-like ball of cel...