When a baby is born in rural Nepal, its severed umbilical cord is commonly tied with a thread of raw cotton. In many cultures, the cord stump is also rubbed with ash, oil, butter, spices, mud or even dung. Throughout the developing world, birth attendants with unwashed hands use dirty knives, scissors, razor blades or broken glass to cut the cord. Freshly cut umbilical cords are attractive breeding grounds for bacteria, and such practices are a major reason why the biggest threat to newborn babies in the developing world is infection.

Medical orthodoxy has long held that umbilical cord stumps should be left untreated until they fall off, and in sterile environments such as Western hospitals, this method works well. Yet for the developing world, doctors are beginning to rethink that recommendation. If cord stumps were instead treated with chlorhexidine, a cheap and widely available antiseptic, it could save 500,000 infant lives per year.

Chlorhexidine, which has been used for years in surgical procedures, is effective, safe, simple to use and requires no refrigeration. It is more powerful than soap and water but less harsh than other antiseptics. It is affordable, too: a single-use tube costs about 23 cents.

In 2002 public health researcher Luke Mullany of Johns Hopkins University and his colleagues began a field trial in Nepal to find out whether using the antiseptic would make a noticeable difference in neonatal mortality. The results were unambiguous: when dabbed onto the umbilical cord stump within the first days of life, chlorhexidine reduced the risk of death by 24 percent. Researchers later estimated that if the antiseptic were used widely in poor countries, both for home births and in health facilities where neonatal mortality is high, it could prevent roughly one in six newborn deaths. “It has the opportunity to be a game changer,” says Carl Bose, a neonatologist at the University of North Carolina at Chapel Hill who was not involved with the field trials.

In Nepal, where most babies are born at home, health care workers in 41 of the country's 75 districts are now distributing free, single-use gel tubes to women in their final months of pregnancy. Western organizations have paid for the effort so far, but the Nepalese government is scheduled to begin funding the program this year and plans to distribute chlorhexidine nationwide by 2015. Similar pilot programs are in the works in Nigeria, Zanzibar and Zambia.

At press time, the World Health Organization is expected to formally recommend that the antiseptic be used during the first week of life in home-birth settings where risk of death is high. Advocates say that this is a good step but point out that the WHO still promotes “dry cord care” (leaving the cord untreated) in low-resource hospitals and clinics. Instead, they say, it should promote chlorhexidine in those settings, too. Antiseptics can increase the time it takes for the cord stump to fall off, but studies suggest the delay poses little risk. “If the WHO doesn't recommend something, it often doesn't happen,” Bose says. “It could be an opportunity lost.”