The ban on growing human embryos in the lab beyond 14 days has been relaxed by an international body of experts, paving the way for research that could help to unpick issues ranging from why recurring miscarriages occur to improving IVF. The decades-old rule is laid down in the law in a number of countries, including the UK and Australia, and was previously stipulated in guidelines from the International Society for Stem Cell Research (ISSCR)..