A recent multi-agency report ranked Indonesia among 10 countries worldwide with the highest number of pre-term births, with 15.5 babies out of every 100 live births born too early -- about 676,000 babies annually, local media reported on Monday.

The World Health Organization defines any birth before 37 weeks (259 days) of pregnancy as pre-term, while a full-term pregnancy is anywhere from 37 to 41 weeks.

Globally some 15 million infants -- more than one in 10 births - -are born too early each year, and more than one million die shortly after birth. Countless others suffer some type of lifelong physical, neurological, or educational disability, according to the report.

Indonesia's rank in the ninth position puts it above Pakistan and below Mauritania. Belarus, Ecuador, Latvia and Finland have among the lowest rates of too-early births among countries that provided the UN data.

"The dominant cause of pre-term births in Indonesia is infections, including vaginal and renal infections," said Ali Sungkar, an obstetrician-gynaecologist and lecturer at the medical school of the University of Indonesia.

"Most of those mothers who give birth to pre-term babies come from low socio-economic backgrounds. They have low body mass index and suffer from anaemia," he was quoted by the Jakarta Globe as saying.

Smoking, alcohol consumption and depression also contribute to pre-term births, and once a woman delivers an infant prematurely, she is more likely to do so again Sungkar said.

He estimated that such births cost the state 10 times more per child than full-term deliveries, and "the government won't have the money to cover all the costs," but added that there was little research available on this.

Indonesia has no universal health insurance, but poor people can get free medical treatment if they present the necessary documents. Patients usually cover around 73 percent of their health costs out of their own pockets, according to government data reported to WHO in 2009.

More than 76 million of Indonesia's 240 million people are covered by Jamkesmas, a health-fee waiver for the poor, but a legislator recently told local media that an estimated 20 million poor people are not covered because their data cannot be verified.

The government has said it will increase the number of people eligible for Jamkesmas to 86.4 million in 2013, in line with updated data collected by the Central Bureau of Statistics. An amount of 7.4 trillion rupiah (about $791 million) has been allocated to health subsidies for 2012, with each qualified family entitled to up to 2.5 million rupiah (about $266).

Sungkar said antenatal care played a key role in preventing pre- term births and more training should be given to midwives and clinic personnel. The Indonesia Health Profile 2010 noted that four out of 10 pregnant women do not make the recommended four antenatal visits.