New York ? Increased contraceptive use has led to fewer abortions worldwide, but deaths from unsafe abortion remain a severe problem, killing 70,000 women a year, a research institute reported Tuesday in a major global survey.

More than half the deaths, about 38,000, are in sub-Saharan Africa, which was singled out as the region with by far the lowest rates of contraceptive use and the highest rates of unintended pregnancies.

The report, three years in the making, was compiled by the New York-based Guttmacher Institute, which supports abortion rights and is a leading source of data on abortion-related trends. Researchers examined data from individual countries and multinational organizations.

The institute’s president, Sharon Camp, said she was heartened by the overall trends since Guttmacher conducted a similar survey in 1999, yet expressed concern about the gap revealed in the new report.

“In almost all developed countries, abortion is safe and legal,” she said. “But in much of the developing world, abortion remains highly restricted, and unsafe abortion is common and continues to damage women’s health and threaten their survival.”

The report calls for further easing of developing nations’ abortion laws, a move criticized by Deirdre McQuade, a policy director with the U.S. Conference of Catholic Bishops’ Secretariat for Pro-Life Activities.

“We need to be much more creative in assisting women with supportive services so they don’t need to resort to the unnatural act of abortion,” she said.