About 70,000 women die every year and many more suffer harm as a result of unsafe abortions in countries with restrictive laws on ending a pregnancy, according to a report.

The total number of abortions across the globe has fallen, the influential Guttmacher Institute says, but that drop relates only to legal abortions and is mostly the result of changes in eastern Europe.

There were 41.6m terminations worldwide in 2003, compared with 45.5m in 1995. But in 2003, says the report, 19.7m of these were unsafe, clandestine abortions. The numbers of those have hardly changed from 1995, when there were 19.9m.

Almost all the unsafe abortions were in less developed countries with restrictive abortion laws.

"Virtually all abortions in Africa and in Latin America and the Caribbean were unsafe," says the report. In Asia, safe procedures outnumbered unsafe because of the large number of legal abortions in China. Most of those in Europe and almost all in North America were safe.

The figures are hard to obtain in countries with restrictive laws from hospitals dealing with women damaged by backstreet or self-induced abortion. But the institute, which has been monitoring the numbers for many years, is confident of the picture it paints and hopes it will influence policy makers.

"Our hope is that the new report will help inform a public debate in which all too often emotion trumps science," said the institute president, Dr Sharon Camp.

Fundamental to turning the tide is preventing unwanted pregnancy, but in many countries there is little advice on family planning and contraceptive products are in short supply. "Women will continue to seek abortion whether it is legal or not as long as the unmet need for contraception remains high," Camp said. "With sufficient political will we can ensure that no woman has to die in order to end a pregnancy she neither wanted nor planned for."

The US has always been the biggest funder of family planning in developing countries, but a significant amount of it stopped under the presidency of George Bush, who reinstated a policy known as the "global gag rule" on arrival in office in January 2001.

It removed funding from any family planning organisation overseas that had anything to do with abortion, including counselling. Although European governments, including the UK, stepped up contributions, funds were short at a time when more couples were becoming interested in smaller families. "It really was a lost decade," said Camp.

President Barack Obama has rescinded the policy and more US funds are expected, but the process of ordering increased contraceptive supplies from manufacturers and getting them to where they are needed will take time.

Where contraceptive use has risen, such as in the former Soviet bloc countries, abortion rates have invariably fallen. Worldwide, the unintended pregnancy rate has dropped from 69 for every 1,000 women aged 15-44 in 1995 to 55 for every 1,000 in 2008. The proportion of married women using contraception increased from 54% in 1990 to 63% in 2003.

However, only 28% of married African women use contraceptives. Lack of availability is the biggest issue.

The report points to a global trend towards the liberalisation of abortion laws, which has allowed women with an unwanted pregnancy to end it safely. Nineteen countries have relaxed their restrictions since 1997. But in three countries, Poland, El Salvador and Nicaragua, tougher legislation has been introduced, the latter two prohibiting abortion even when the woman's life is at risk.

"We have seen an increase in women's deaths and teenage suicides in Nicaragua," said Dr Kelly Culwell, of the International Planned Parenthood Federation at the report's launch.

Camp deplored the exit of the pharmaceutical companies from research and development work on contraceptive products. "There used to be 13 major pharmaceutical companies with full-blown programmes of contraceptive R&D. Now there are none," she said.

Yet there was a real need for products women could use if they were having occasional rather than regular sex apart from the condom, which requires the consent of the man.