Research published in the Journal of the Royal Society of Medicine said the evidence to support the use of misoprostol is "at best inconclusive", yet it is increasingly used in poorer countries to prevent postpartum hemorrhage (PPH).

"Developed countries would not dream of giving women misoprostol during labor on the basis of the current evidence, yet industry and health practitioners are pushing it hard in developing countries," said Allyson Pollock of Queen Mary University of London, who led the study.

Although there is no proper evidence of benefit, the WHO and some countries have misoprostol on their Essential Medicines Lists, Pollock said, and countries such as Nepal, India and Uganda are promoting and using it.

She called on the WHO urgently to review its decision to put the drug on its Essential Medicines List - a list of drugs the U.N. health agency says are needed to "satisfy the priority health care needs of the population".

Misoprostol, also sold under the brand name Cytotec by Pfizer, was originally developed to treat gastric ulcers but is increasingly used to prevent dangerous bleeding after childbirth. It is now manufactured and sold by various generic drugmakers round the world.

Pollock and fellow researchers analyzed 172 previous studies on the use of misoprostol during labor and found that only six had enough information to say whether or not the drug was effective in preventing PPH in rural and community settings in poor countries.

These six studies did not provide enough evidence that the drug worked, the researchers found.

According to the WHO's latest estimates, there were 342,900 deaths related to pregnancy and childbirth in 2008, most of them in developing countries. A quarter of these are thought to be linked to women hemorrhaging after giving birth.

Experts say the main risk factor for post partum hemorrhage is anemia, which can be easily treated if it is diagnosed.

But without antenatal screening for anemia it is impossible to find women who may have it and would be at increased risk of life-threatening bleeding during labor.

Pollock said one reason why misoprostol is popular in developing countries is that it is a fairly stable drug that comes in pill form and does not degrade if it is not kept in cold storage.

Because the drug does not have to be given intravenously, it is more likely to be used outside hospitals in places like patient's homes and local clinics when women go into labor.

Pollock said, however, that the drug was being misused.

"Countries should be concentrating on improving their primary care facilities, rather than thinking there is a pill to prevent every ill," she said in a statement about the findings.

"Misoprostol is being used inappropriately at present, and the money being spent on ... the drug would be better spent elsewhere, for instance in ensuring there are skilled attendants during delivery and adequate antenatal services that can detect and help to prevent complications."

(Reporting by Kate Kelland, editing by Tim Pearce)

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