Today there are about ten businesses in the UK offering to freeze and store cord bloodand industry insiders estimate that up to 100,000 parents have chosen to do so in the UK. The global stem-cell market is forecast to trebleto a staggeringā40 billion by 2015.

　　Cord blood contains embryonicstem cells. They can be made into more specialised cells and can reproduce copies of themselves almost indefinitely. There is currently research into a host ofapplications – from growing new organs to curing paraplegia. In theory, stem cells treat disease by replacing damaged or diseased cells. They are used in bone-marrow transplants to treat leukaemia– but in these cases, donor blood taken in the usual way is used to harvest the stem cells.

　　To bank cord stem cells, the cord blood is extracted minutes after the birth of the baby and rushed by courierto be processed. Any cells that could be of future value are frozen at minus 180C and can then be stored for 25 years.

　　There are no published examples of a child’s own cord blood being used to cure them of leukaemia – one of the most common childhood diseases mentioned by the banks in their sales pitches. There are two cases of successful sibling transplants for children with the hereditary condition thalassemia, where the body makes an abnormal form of haemoglobin– the protein in red blood cells that carries oxygen. These were carried out in Singapore and Germany.

　　Lavish promises of future treatments tend to be based on preliminary clinical trials – and should a child fall ill today, in many cases the technology doesn’t exist to actually use the harvested stem cells. In fact, some experts believe that reintroducing banked cord blood into a child could increase the chance of relapse– as disease-causing cells that existed from birth would be stored alongside useful stem cells.

　　‘Parents are worried that by not storing cord blood, they aren’t giving their child the best possible chance for future health,’ says leading consultant gynaecologistand obstetricianMr Dickinson Cowan, who admits that when he first came across private banking, he thought it was a good idea. ‘I’d never recommend it now,’ he says.

　　现在英国约有十家公司提供冷冻储存脐带血的服务，业内人士估计，英国有10万父母选择为孩子保存脐带血。据预测，全球干细胞市场份额在2015年将多达400亿英镑，增至原来的三倍。

　　脐带血含有胎儿的干细胞。它们可以发展成更专门的细胞，而且几乎能无限地被复制。目前有针对一系列应用的研究——从生成新器官到治疗截瘫。理论上，干细胞可通过替换受损或病变的细胞来治疗疾病。它们被用在骨髓移植中，用来治疗白血病。不过，在这些情况下，干细胞从捐赠者按正常方式抽取的血液中获得。

　　为了储存脐带血干细胞，脐带血在婴儿出生后数分钟内被抽取，并迅速由专递员送去处理。任何在未来会有使用价值的细胞都要在零下180摄氏度的环境中储存，这样才能保存25年。

　　当前公开报道中还没有能够用孩子自己的脐带血治疗白血病的例子。白血病是脐带血库在他们的广告宣传中提到的最常见的儿童疾病。曾经有两例患遗传的地中海贫血病的小孩被成功移植了兄弟/姐妹的干细胞。地中海贫血病患者的身体会产生异常的血红蛋白(血红蛋白是红细胞中运载氧气的蛋白质)。这两次成功移植分别发生在新加坡和德国。