Globally, about 15 million babies are born before 37 weeks gestation annually and one million die.
The findings showed that waiting 60 seconds before clamping the umbilical cord after birth instead of clamping it immediately reduced hospital mortality by a third and is safe for mothers and pre-term infants.
Further, delayed clamping also reduced subsequent blood transfusions and increased neonatal hematocrit — the proportion, by volume, of the blood that consists of red blood cells — confirming that placental transfusion occurred.
"We estimate that for every thousand very preterm babies born more than ten weeks early, delayed clamping will save up to 100 additional lives compared with immediate clamping," lead author David Osborn, Associate Professor at the University of Sydney and a neonatal specialist at Royal Prince Alfred Hospital.
"This means that, worldwide, using delayed clamping instead of immediate clamping can be expected to save between 11 000 and 100 000 additional lives every year," Osborn added.
For the study, approved for publishing in the American Journal of Obstetrics and Gynecology, the team assessed morbidity and mortality outcomes from 18 trials comparing delayed versus immediate cord clamping in nearly 3000 babies born before 37 weeks' gestation.
Another study, published in the New England Journal of Medicine, enrolled 1566 babies born over ten weeks early in 25 hospitals in seven countries and reported that delayed clamping might reduce mortality rate by 2.6 percent.