(CNN) - Laws that seek to limit abortions around the world may not lower the rate of abortions but could make them less safe, according to a new report that illustrates the trend.
In countries with the fewest restrictions, only 1% of abortions were the "least safe" kind from 2010 to 2014. That number jumps to 31% in the most restrictive countries, according to the report, released Tuesday by the Guttmacher Institute, a reproductive rights think tank.
During the same period, abortions happened roughly as frequently in the most restrictive countries as they did in the least restrictive: 37 versus 34 abortions each year for every 1,000 women aged 15 to 44.
"Restricting abortion laws does not eliminate the practice of abortion," said Gilda Sedgh, principal research scientist at the Guttmacher Institute and one of the report's authors.
Abortion rates have dropped globally over the past 25 years, driven by increased and more effective contraceptive use, Sedgh said. Procedures have also become safer overall, in large part due to the increasing use of medications that are effective in terminating pregnancy, the report said.
A study last year by researchers at the Guttmacher Institute and the World Health Organization found that 45% of abortions performed between 2010 and 2014 were considered unsafe, meaning they didn't use both a recommended abortion method and a trained provider.
Unsafe abortions can lead to complications, such as heavy bleeding, infection, damage to internal organs or an incomplete abortion, according to the WHO. Complications can sometimes be fatal.
Countries that have seen falling abortion rates since the '90s are more likely to be developed countries, which tend to have fewer abortion restrictions and wider access to contraceptives. Abortion rates in developing regions haven't changed much overall.
About 42% of women of reproductive age live in countries "where abortion is highly restricted," according to the report, versus 37% who live "where abortion is available without restriction as to reason -- with maximum gestational limits specified in almost all cases."
US abortion rates have hit a historic low in recent years, according to another report last year by the institute.
However, advocates have warned that increasing restrictions by individual states could delay care and put some women's health at risk.
"The United States has been adding restrictions on a state-by-state basis at an alarming rate over the last few years," said Dr. Jody Steinauer, director of the Bixby Center for Global Reproductive Health at the University of California, San Francisco. Steinauer, a practicing ob-gyn, was not involved in the new report.
"The bottom line is that these restrictions ... cause unnecessary harm and delay women in accessing the care they need," Steinauer said.
On Monday, Mississippi Gov. Phil Bryant signed a bill that prevents women from getting abortions after 15 weeks of pregnancy. This would have given Mississippi the distinction of having the earliest abortion ban in the country, but a federal judge issued an order Tuesday temporarily blocking it.
Research has shown that restrictive laws in places like Ohio, Utah, Wisconsin and Texas did not improve outcomes and in some cases led to more hardships such as delayed abortion care, more side effects and higher costs for women.
At the same time, between 2000 and 2017, 28 countries around the world modified their abortion laws, and all but one -- Nicaragua -- broadened access to abortion, the report says. Nepal came the furthest of any country, removing its complete ban on abortion in favor of no restrictions on why someone might seek to terminate their pregnancy.
Some countries, Sedgh said, "are moving toward liberalizing abortion laws, making it legal under broader ground."
"At the same time, in some countries with liberal abortion laws like the US and some former Soviet countries, ideology is making its way into legislation, and more and more restrictions are being imposed."
These restrictive policies are "based on this myth that abortion is a complicated procedure or an unsafe procedure," Steinauer said.
"In fact, it's just the opposite. It is an extremely safe procedure," she said. "It's even safer than a dental extraction."
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