The trial, which involved 334 infants, found that it reduces the chance of deficiency at four months.
The researchers wrote: ‘Iron deficiency even without anemia has been associated with impaired development among infants.’
They continued: ‘Our results suggest that delayed cord clamping also benefits infant health in regions with a relatively low prevalence of iron deficiency and should be considered as standard care for full-term deliveries after uncomplicated pregnancies.’
Half the infants in the study were randomly assigned to have their cords clamped within 10 seconds of delivery.
For the other half, umbilical cords were left to pulsate for three minutes or longer before clamping.
Tests showed that iron levels in the two groups were similar two days after delivery.
But, four months after birth, infants whose cords were clamped early had higher levels of iron deficiency.
While researchers found iron levels in the blood were almost 50% higher in the delayed-clamping group.
Lead author Ola Andersson, a pediatrician from Sweden, said it is widely believed that delayed clamping causes jaundice.
However, the study uncovered no evidence of this, or any other adverse effects.
The study is published in the British Medical Journal