Less than one percent of women getting a medication-induced abortion at Planned Parenthood had a serious side effect or a failed abortion, according to a new study.

Researchers found the rate of abortion-related complications sending women to the emergency room or requiring a blood transfusion, for example, was one in 625 during 2009 and 2010.

“At Planned Parenthood, medical abortion is extremely safe,” said reproductive health researcher James Trussell from Princeton University in New Jersey, who worked on the study.

“The most common adverse outcome is just continuing pregnancy,” he added. “It doesn’t work 100 percent of the time.”

The data came from 233,805 first-trimester abortions done using the drugs mifepristone and misoprostol at 317 Planned Parenthood health centers.

In one in 200 of those cases, women had an ongoing pregnancy that wasn’t terminated after two attempts with medication, the researchers reported Thursday in Obstetrics & Gynecology.

Eight women each year had an ectopic pregnancy - when the embryo implants outside the uterus - that was diagnosed after the attempted abortion. One died from related complications.

Of the 233,805 abortions during the study period, 385 women had a serious side effect, including 238 who sought ER treatment, 135 who were admitted to the hospital, 114 who had a blood transfusion and 57 who required intravenous antibiotics. All of those women survived.

“This continues to show that medical abortion is a very, very safe option for women,” said Dr. Debra Stulberg, who studies disparities in reproductive health at the University of Chicago and wasn’t involved in the new study. “That’s really the take-home point.”

She told Reuters Health medical abortions are still less common than surgical ones in the U.S., but that they’re becoming relatively more frequent and “women should be reassured” based on these and other data.

Surgical procedures are also known to be safe, researchers noted. One study from 2010 found that about one percent of women having a surgical abortion before their 16th week of pregnancy had a complication that could require intravenous fluid, and just one in 300 had a major complication.

One limitation, the study team noted, is that not all women checked back after the abortion or had follow up medical records available - so it’s possible more complications could have occurred that weren’t recorded.

Planned Parenthood staff members were required to make three attempts to reach any patients who didn’t return for follow up visits under the organization’s medical standards and guidelines.

“We assume that if anything had happened, that people would get back in touch with Planned Parenthood,” Trussell told Reuters Health.

“The reason that people often skip their follow up is, they’re fine.”

Two of the study’s authors are Planned Parenthood employees, and Trussell is a member of the National Medical Committee of Planned Parenthood Federation of America. Another author receives compensation from the U.S. distributor of mifepristone, Danco Laboratories.

The medication regimen used by Planned Parenthood - and many other abortion providers - is slightly different than the U.S. Food and Drug Administration-approved drug course because it includes lower doses of mifepristone and at-home use of misoprostol.

There have been attempts in some states to force providers to use the approved regimen, according to Trussell, even though so-called off-label use of the drugs is allowed. There’s no evidence the FDA regimen is safer, he said - but it is more expensive.

“It has nothing to do with medicine,” he said. “It’s just nuisance.”

Medical abortions done at Planned Parenthood run for about $300 to $800, according to its website.

The researchers said their findings don’t support laws restricting the drugs’ use.

“Mandating the FDA-approved regimen, without a scientific basis, does not protect patients from unsafe abortion; it only limits access to safe and effective medical abortion for women desiring a pregnancy termination,” they concluded.

SOURCE: Obstetrics and Gynecology, online December 20, 2012.