* Abortion rates fall but unsafe abortions still kill 70,000

* Women in countries with restrictive laws are at risk

* Dangerous abortion imposes heavy economic, health burden

LONDON, Oct 13 (Reuters) - Increased use of contraceptives has pushed global abortion rates down, but unsafe abortions kill 70,000 women each year and seriously harm or maim millions more, a global report said on Tuesday.

Despite easier access to abortion with restrictions being relaxed in many countries, the number of abortions fell from an estimated 45.5 million in 1995 to 41.6 million in 2003, the report by the U.S.-based Guttmacher Institute said.

But the study found a stubbornly high number -- almost 20 million -- of unsafe abortions, mostly in poorer countries and often carried out by the women themselves using inappropriate drugs or herbal potions, or by untrained traditional healers.

"It is significant and tragic that while the overall rate of abortion is on the decline, unsafe abortion has not declined," said Sharon Camp, president of the Guttmacher Institute, a think-tank which studies sexual and reproductive health.

"Legal restrictions do not stop abortion from happening, they just make the procedure dangerous. Too many women are maimed or killed each year because they lack legal abortion access," she told a news conference in London.

CONTRACEPTION CHEAPER

The researchers said 40 percent of women still live in nations where abortion is highly restricted, and called for greater effort to improve access to contraception to prevent some of an estimated 76 million unwanted pregnancies each year.

They also said that in the developing world as a whole, healthcare for women harmed by unsafe abortions costs an estimated $500 million.

"Behind every abortion is an unwanted pregnancy," said Akinrinola Bankole, the Guttmacher's international research director.

He said developing countries and donor nations should look at the figures, which he said clearly demonstrated that "preventing unwanted pregnancy is cost-effective".

In Nigeria, for example, a recent study showed the costs of treating women for complications caused by botched abortions were some $19 million, while it would cost only $4.8 million to provide contraception for those who wanted it.

The researchers said preventing the need for abortion entirely was unrealistic, but said eliminating unsafe abortion by improving access to contraception and increasing pressure to lift abortion restrictions was a worthwhile and achievable goal.

"Women will continue to seek abortion whether it is safe 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."

Camp pointed to the Netherlands as an example of best practice and said she hoped to see global abortion rates come down from the current rate of 29 per 1,000 women aged between 15 and 44 rate, to the Dutch rate of around 10 per 1,000.

"It's a long way off, but it's not impossible," she said.