New mothers should be discouraged from banking their umbilical-cord blood as insurance in case their child gets ill later in life, an expert says.
Umbilical cord blood is rich in therapeutic stem cells
The blood is highly unlikely to be used and the practice could impede care on the maternity ward, consultant obstetrician Leroy Edozien warns.
Women should instead donate altruistically to public blood banks, he told the British Medical Journal.
Cord blood is rich in stem cells that can treat diseases such as leukaemia.
Bone marrow can also be used, but cord blood is cheaper and easier to obtain and is less likely to cause health problems in the recipient.
Mothers can donate their umbilical cord blood to the NHS Cord Blood Bank with the aim of helping others.
Those from families with a high risk of a genetic disorder can also store the blood with the NHS in case they need to treat one of their children in the future.
Increasingly, other mothers have become interested in storing their cord blood in case one of their children falls ill in the future.
Some believe it could also be a good insurance policy for their own future health, should stem cell technology ever provide a cure for conditions such as cancer.
Commercial companies exist that offer personal cord banking services for a fee of up to £1,500.
Numerous medical bodies, including the Royal College of Obstetricians and Gynaecologists (RCOG), advise against this because of "insufficient scientific base and logistic problems of collection for NHS providers".
For example, the consent procedure and associated paperwork puts extra strain on already overstretched midwifery staff.
And the cord blood must be collected immediately after the baby is delivered - a time when medical staff have to focus on the needs of the mother and baby.
Mr Edozien, who works at St Mary's Hospital in Manchester, said: "Time spent on collecting cord blood is time away from the care of this mother, the baby, and, critically, other patients."
CORD BLOOD STORAGE
The chance of an individual using personal cord blood for a blood cell disorder before the age of 20 is estimated to be between 1/20,000 to 1/37,000
He warned there was also a risk in these circumstances that the cord blood could be contaminated or mislabelled, which could lead to legal action.
"These logistical problems do not apply to altruistic donations because the blood is collected by specially trained staff who are not involved in routine care and there is no imperative to obtain a sample from any particular woman," he said.
Professor Peter Braude of the RCOG says private banks would not be needed if the NHS cord blood bank was large enough.
The NHS collects about 2,000 cord blood samples per year, and has collected over 17,000 since it was established in 1996.
Altruistic donations can be made at three hospitals around London - Barnet General, Northwick Park, and Luton and Dunstable - and soon a fourth, Watford General.
A spokeswoman from the commercial firm UK Cord Blood Bank, one of the leading private banks in the UK, said: "Private banks in the UK have an important role to play, particularly as the NHS has limited resources."
She said the UKCBB had taken a steps to address concerns associated with private cord blood collection, including offering the services of an independent nursing agency to carry out the collection.