Washington  - More than 1 million babies die every year worldwide because they are born too early, according to a global survey released Sunday by the March of Dimes organization.

The white paper report, to be presented at a conference on birth defects in the developing world starting this week in New Delhi, said that the 1 million deaths represent about 28 per cent of total newborn deaths in the first month of life.

Premature births are those which occur before the 37th week of a normal 40-week pregnancy.

The highest preterm birthrate is in Africa, with 11.9 per cent of all births, followed by North America, Asia, Latin America and the Caribbean, Oceania (Australia and New Zealand combined), and Europe.

The data was taken from information compiled by the World Health Organization.

The report found that preterm births are increasing.

In the United States, for example, the rate has increased 36 per cent in the past 25 years. Key factors in the US rise included the growing number of women over age 35 who bear children and the growing use of "assisted reproduction techniques" which lead to more multiple births.

"Premature births are an enormous global problem that is exacting a huge toll emotionally, physically, and financially on families, medical systems and economies," said Dr Jennifer Howse, president of the March of Dimes, in a press statement. "In the United States alone, the annual cost of caring for preterm babies and their associated health problems tops 26 billion dollars annually." (dpa)