Each year, about 1 million children worldwide die after being born prematurely, yet two strategies that are effective in preventing these deaths are largely underused, researchers have found.

Before delivery, injections of corticosteroids help fetal lungs to mature and reduce respiratory distress, mortality and infections in the 48 hours after birth. Drugs to delay labor can give corticosteroids more time to take effect and allow for a transfer to a more intensive health care setting, if necessary.

Yet the largest study to examine use of these drugs worldwide, which included data from 359 facilities in 29 countries, found that only 18 percent of women in spontaneous premature labor received both treatments, and 42 percent had neither. The study was published this month in The Lancet.

"Current use of antenatal corticosteroids is too low, and further research is needed to understand why, and how it can be improved," said Dr. Joshua Vogel, the study's lead author and a technical officer in the Department of Reproductive Health and Research at the World Health Organization.

The use of medications to delay delivery, called tocolytic drugs, is more controversial, Vogel noted. "Despite a large number of trials, it isn't clear if the drugs to delay delivery themselves actually improve the outcome for the baby," he said.

The study found that the use of these drugs was infrequent, and when they were given, less effective or potentially harmful ones were administered.

For example, betamimetic drugs like terbutaline were often given to women in premature labor, even though these medications have more known side effects like chest pain and difficulty breathing. Nifedipine, a calcium-channel blocker, is the recommended drug, Vogel said.

Just as worrisome, he added, more than a third of women in premature labor received ineffective treatments like bed rest.

New York Times