LONDON (Reuters) - A new formulation of a drug to prevent excessive bleeding in women after they give birth could save thousands of lives in poorer countries, according to a study co-led by the World Health Organization (WHO).

The drug, called carbetocin and made by Ferring Pharmaceuticals, could prove a useful alternative to oxytocin - currently recommended as the first-choice medicine for preventing excessive bleeding after childbirth.

Oxytocin needs to be transported and stored at between 2 and 8 degrees Celsius, making it tricky to use in many poor countries where infrastructure and power supply can be limited.

This means many women don’t get a life-saving drug during childbirth, the WHO researchers said. Other women might get it only to find it has lost its efficacy due to heat exposure.

The study, published in the New England Journal of Medicine on Wednesday, found that carbetocin - a heat-stable drug - is as safe and effective as oxytocin in preventing postpartum bleeding.

The drug is robust and stable enough to be transported and used in hot climates where cold storage can be a problem. It doesn’t require refrigeration and retains efficacy for at least three years even at 30 degrees Celsius (86°F) and 75 percent humidity.

Tedros Adhanom Ghebreyesus, the WHO’s director-general, said the finding was “a truly encouraging new development” that could “revolutionize our ability to keep mothers and babies alive”.

Around 70,000 women die each year worldwide due to post-partum hemorrhage. Their deaths also increase the risk that their newborns will also die within a month.

The trial looked at 30,000 women who gave birth vaginally in 10 countries: Argentina, Egypt, India, Kenya, Nigeria, Singapore, South Africa, Thailand, Uganda and Britain.

Each woman was randomized to get either a single injection of heat-stable carbetocin or oxytocin immediately following the birth of her baby. The results showed both drugs were equally effective in preventing excessive bleeding after childbirth.

The next step will be to submit carbetocin for regulatory review and approval by countries wishing to use it, the WHO said, after which it will be considered for potential addition to the WHO’s list of recommended drugs for post-partum bleeding.