Every two months, the doctors collected information about the health of the babies - what they ate, how much they grew, and if they got sick.
They also measured the amount of iron the babies had in their bodies.
Doctor Kathryn Dewey helped to lead the research.
She said the results were very encouraging.
“The results show that the two minute delay in cord clamping increased the child’s iron supply by 27 to 47 milligrams of iron.
This is the same as one to two months of newborn iron requirements.
This could help prevent iron deficiency from developing before six months of age ...
After that, babies can have food that has more iron in it.”
Doctors have known about some positive results of delayed cord clamping for over thirty years.
They knew that the baby received more blood the longer he was attached to the umbilical cord.
But the effects have not been proven until now.
The research showed that this small change in the process of birth had lasting results.
And doctors could even see the results six months later!
Anaemia is common in every part of the world.
But it is especially common in developing countries.
Many people living in these areas are not able to pay for treatments for anaemia.
So this simple, painless, and low-cost process is very helpful.
Doctor Dewey says: “By simply delaying cord clamping for this short time, we can provide the newborn with the extra blood, and the iron it contains, from the placenta.
This is an efficient, low-cost way to intervene at birth without harm to the newborn or the mother.”
Delayed cord clamping is one way to help keep a newborn from becoming anaemic.
But babies also need to continue getting iron as they grow.
Feeding a baby breast milk is one good way to make sure she gets the nutrients she needs.
The next step for Doctor Dewey and her research team is to spread information.
They hope to tell other doctors about the encouraging results of delayed cord clamping.
And they hope to increase the use of this method in different parts of the world.