Prematurity is the leading cause of newborn deaths, according to an international report that set new goals for all countries on reducing the problem.

Worldwide, 15 million of the 135 million babies born in 2010 were premature, and of those, 1.1 million died, according to Wednesday's report by the March of Dimes, United Nations, Save the Children and World Health Organization.

"Being born too soon is an unrecognized killer," said Dr. Joy Lawn, co-editor of the report.

It's the first ranking of preterm birth rates by country, the groups said.

For countries like Canada with a newborn mortality rate of less than five per 1,000 live births, the goal is to eliminate preterm births before 37 weeks of pregnancy.

Survivors face a lifetime of potential disability. About a quarter born earlier than 28 weeks are blind or visually impaired, five to 10 per cent are deaf, 40 per cent have chronic lung disease and an unknown number have learning impairments.

Canada's rate was 7.78 per cent.

The 10 countries with the highest number of preterm births include Brazil, the United States, India and Nigeria.

Rates of preterm birth ranged from four per cent in Belarus to 18 per cent in Malawi and generally mirrored poverty.

The U.S. rate was 12 per cent, the worst among G8 countries.

In high-income countries, the increases in the number of preterm births are linked to the number of older women having babies, increased use of fertility drugs and the resulting multiple pregnancies, and lifestyle challenges such as obesity, smoking and diabetes.

Medically unnecessary inductions and C-sections before full term have also increased preterm births.

The report's authors championed two strategies: prevention and care.

Prevention includes education on family planning and adolescent friendly services. Care ranges from resuscitation of infants and kangaroo care — holding newborns skin to skin on the mother's chest to keep them warm, making frequent breastfeeding easy, preventing infections and providing constant maternal supervision.

Kangaroo care alone could save 450,000 lives a year, the authors said.

"Weighing less than a packet of sugar at only 2.2 poundsTantufye survived with the help of kangaroo mother care," her mother Grace, in Malawi, said in the report. She survived against the odds and is now a healthy young girl.

Giving steroid injections for mothers in premature labour that cost $1 per injection could save almost 400,000 babies a year by helping develop immature fetal lungs and prevent respiratory problems.

The report was funded by 40 organizations, including the government of Canada.