A drug used to treat severe bleeding could save thousands of lives for mothers giving birth.

A global trial of the drug found it reduced the risk of bleeding deaths during childbirth by nearly one-third. The study involved 20,000 women in 21 countries, mainly in Africa and Asia.

The trial was carried out by London's School of Hygiene and Tropical Medicine. The drug is called tranexamic acid. It is low-cost and researchers said it does not cause serious side effects for mothers or babies.

The drug was first developed by Japanese scientists in the 1960s, but no long-term studies of it were completed until now. The drug is used to treat mothers for severe bleeding during childbirth, also known as postpartum hemorrhage.

Postpartum hemorrhage is the leading cause of maternal death worldwide, according to the World Health Organization. More than 100,000 women die of the condition each year.

Haleema Shakur is the project director for the trial. She says despite medical advances in many countries, severe bleeding after childbirth remains a big problem in some parts of the world.

"It's one of the biggest killers of mothers. You know, mothers go into childbirth expecting everything to happen normally. But in Africa and Asia, about 10 percent of women will end up with severe bleeding."

The drug works by stopping blood clots from breaking down after a mother gives birth. The treatment can prevent the need for doctors to perform surgery to find the source of bleeding.

Shakur said the best results were reported when the drug was given to women as soon as possible after childbirth.

"The earlier you give it – so within the first three hours of giving birth – the better the effect. Overall we saw a 20 percent reduction in death due to bleeding, whereas in women who received the treatment within the first three hours, it was 30 percent."

The next step will be to get the drug where it is needed and provide training to doctors and nurses on how to use it.

During the trial, women were given the drug through an intravenous (IV) line in a hospital setting. But researchers are looking for easier ways to administer the drug so it can be more widely used in small clinics and rural areas.

I'm Bryan Lynn.

Henry Ridgwell reported this story for VOA News. Bryan Lynn adapted the report for Learning English. Hai Do was the editor.