Procedure distracts midwives at an important stage after the birth, health professionals say
Midwives and doctors point out that it's unlikely a child will develop a life-threatening illness, thus needing the blood.
The trend of collecting blood from the umbilical cord to protect against future illnesses is putting mums and newborns at risk, doctors and midwives warn.
Over the past decade, around 11,000 mums have had the umbilical cord blood extracted minutes after giving birth.
The blood, which contains stem cells, is then stored to treat illnesses their babies may develop in later life, such as leukaemia. It can be stored at a private firm for up to 25 years at a cost of up to £1,500.
But the Royal College of Midwives and the Royal College of Obstetricians and Gynaecologists say midwives should be devoting their attention to checking the newborn is properly breathing and the mum is not bleeding heavily, instead of collecting blood.
Sue Macdonald, education and research manager at RCM says: "A lot of midwives are being asked to collect blood. The focus should be on the mother and baby."
Mums can also donate their umbilical cord blood to the NHS Cord Blood Bank to treat leukaemia sufferers as well as patients with rare blood disorders.