New research suggests that leaving the cord intact for three minutes increases the baby's iron levels and reduces the risk of anaemia, Liverpool University?s Dr Andrew Weeks said in a report published in the British Medical Journal.
Babies born prematurely would especially benefit from delayed clamping, Weeks said, adding to the controversy over when is the best time to cut the maternal tie.
Weeks estimates that around half of maternity units in the UK cut the cord immediately after the baby is born but said that while trials have shown that mothers did not suffer ill effects from early clamping, babies could benefit from leaving the cord intact a little longer.
Leaving it for a while sends oxygen-rich blood to the lungs until the baby's breathing is fully established and increases iron levels.
Weeks admits delayed clamping may be more difficult to achieve with premature babies or babies born with caesareans, even though these babies would probably benefit the most from it.
"There is now considerable evidence that early cord clamping does not benefit mothers or babies and may even be harmful," he told the Journal.
"Both the World Health Organisation and the International Federation of Gynaecology and Obstetrics have dropped the practice from their guidelines.
"It is time for others to follow their lead and find practical ways of incorporating delayed cord clamping into delivery routines."
There have been concerns that early clamping could cause a condition leading to jaundice, but Weeks argues that trials have shown this is not the case.