Major study reveals one in 10 babies are born pre-term, but deaths can be avoided with better availability of inexpensive treatments

Some 15 million babies are born too soon every year, and 1 million of them will die while many others are disabled – but many of these premature births and deaths are preventable, according to the first report into the global scale of the problem.

More than one in 10 babies are premature, which means they are not fully grown and are highly vulnerable to infections and birth complications. But about 75% of the deaths could be avoided if a few inexpensive treatments were available across the globe, says the report from the US March of Dimes Foundation, the Partnership for Maternal, Newborn and Child Health, Save the Children and the World Health Organisation.

The numbers are going up almost everywhere, including in the developing world, where the rate of caesarean sections, as women elect to have their baby at a time of their own choosing, has soared. The UK rate rose from 12% to 24% between 1990 and 2010. Babies are delivered at an estimated 40 weeks gestation but may in fact be several weeks less. The rise in the number of older mothers, who are more likely to give birth prematurely, is also contributing, as are fertility drugs and multiple births through IVF.

In poor countries, where most of the deaths occur, the main causes of premature delivery are infections, malaria, HIV and the high number of adolescent girls getting pregnant. There is a huge difference in survival among the most premature. In rich countries, 90% of babies born before 28 weeks live. In poor countries, only 10% will do so.

Preterm births world map

"Being born too soon is an unrecognised killer," says Dr Joy Lawn, co-editor of the report and director of global evidence and policy for Save the Children. "Pre-term births account for almost half of all newborn deaths worldwide and are now the second leading cause of death in children under-five, after pneumonia."

Lawn has led the team that pulled together the first-ever country estimates of premature births. "It is bigger than we thought it was," she said. "People are shocked."

She has the trends for 65 countries – the data over the 20 years from 1990 to 2010 was not sufficiently reliable, although there are 2010 figures for 184 countries.

"People think the deaths are inevitable. That is the other big message. They are not inevitable – 84% of the pre-term births are moderately pre-term," she said.

In fact, these overlooked premature births are a major factor in child mortality figures, which there is a global move to try to reduce in accordance with the UN's Millennium Development Goals. With other causes of child mortality coming down thanks to vaccinations, anti-malarial bednets and other interventions, nearly 40% of all deaths in under-fives occur in the first month of life.

But in many countries, premature babies – defined as less than 37 weeks gestation – are not expected to survive. Lawn tells of when she worked in Ghana. "There were twins of 30 weeks who were put in the disposal," she said. "Intensive care is rationed. People do not think there is anything they can do."

The report argues that is not the case. Kangaroo mother care, where the tiny baby is placed skin to skin on the mother's chest and stays there for weeks, until they are at the stage where they would have been born, is being taken up in African countries. "That for me has been so inspiring," said Lawn. Trial evidence has shown that it halves the death rate for small babies compared with being in an incubator. The babies gain more weight and feed better.

Steroid injections costing just $1 (60p) a shot, given to women in premature labour, help develop the baby's lungs so they can breathe at birth. This is routine in the developed world but only available for 10% of premature babies in developing countries. That alone could save 400,000 lives a year. Antibiotics can help prevent and treat infection, and antiseptic cream can ensure the cord does not get infected.

Even in developed countries, the rates of pre-term baby deaths are too high among some communities. In the US the pre-term birth rate in 2009 for African Americans was 17.5% compared with 10.9% for white Americans. The age of the mother made a significant difference. In the US the premature birth rate for women aged 20 to 35 was between 11-12% but rose to over 15% for women under 17 and over 40.

The special care baby charity Bliss said the UK rate was also too high. "It is worrying that at 7.8%, the UK's pre-term birth rate is significantly higher than countries such as Sweden, Norway and Ireland, and highlights the need for well co-ordinated and high quality antenatal care for all women identified as high risk," said its chief executive, Andy Cole.