"The legal status of abortion has never dissuaded women and couples, who, for whatever reason, seek to end pregnancy," Beth Fredrick of the International Women's Health Coalition in the United States said in an accompanying commentary.

Abortion accounts for 13 per cent of maternal mortality worldwide. About 70,000 women die every year from unsafe abortions. An additional five million women suffer permanent or temporary injury.

"The only way to decrease unsafe abortion is to increase contraception," said Sharon Camp, president and chief executive officer of the Guttmacher Institute.

Camp said that more countries are allowing women to have abortions legally, but many women only receive medical attention after a procedure has gone wrong. "I don't think women should have to hurt themselves before they get medical treatment," she said.

"The continuing high incidence of unsafe abortion in developing countries represents a public health crisis and a human rights atrocity," Fredrick wrote.

Abortions have decreased worldwide

The number of abortions has dipped from about 46 million worldwide in 1995 to just under 42 million in 2003. But there was no change in the rate of unsafe abortions, with 48 per cent of all abortions deemed unsafe.

Nearly 97 per cent of all unsafe abortions were in poor countries.

The vast majority of abortions – 35 million – were in the developing world.

The study defined unsafe abortions as those performed either by people lacking the necessary skills or in an environment that does not conform to minimum medical standards.

In eastern Europe, there are more abortions than live births: 105 abortions for every 100 live births, the research found. In western Europe, there are 23 abortions for every 100 live births.

In North America, there are 33 abortions for every 100 live births, while in Africa, where abortion is illegal in most countries, there are 17 abortions for every 100 live births.