An estimated 50 percent of women who seek one abortion, will have a repeat one, according to the Guttmacher Institute, which promotes sexual and reproductive health. About 10 percent of those women will have three or more.
Its 2006 report found that most of these women were over age 30 and using contraception at the time of conception.
Little is known about these women, although they may be "perceived as having difficulty practicing contraception," or using abortion as a method of family planning, according to the report.
"A lot of times the circumstances are unusual and complicated," said Rachel K. Jones, a senior research associate who co-authored the report. "There's always a lot more going on than someone who does not want to use contraception."
An American Psychological Association task force concluded that mental health problems are "not a direct result" of choosing to have one abortion.
But the 2008 report did note that many "confounding factors might indicate mental problems" in women who have repeat abortions.
"The research is not really great," said APA spokesman Kim Mills. "It's very hard to tease out."
Vilar's pregnancies became compulsively self-destructive: After her 9th and 10th abortions, she "needed another self-injury to get the high."
"In the beginning I was taking pills and I'd skip a day or two or give up one month," she said. "I'd think I'll be better next time. But slowly, my days took on a balancing act and there was a specific high. I would get my period and be sad, then discover I was pregnant, being afraid, yet also so excited."
Vilar said many women who have repeat abortions show a certain "recklessness."
Such was the case with Mary, a Florida college student who did not want to use her real name, who had her first abortion in 2006 when she was 21.
"It didn't seem like the right choice to have a baby then," she told ABCNews.com. But she got pregnant again with the same boyfriend a month later and without telling him, aborted.
"I felt it wasn't something I wanted to go through again, that I wanted to be more careful," said Mary. "It's a physically painful thing to do -- not something I'd ever want to use as a form of birth control. Who wants to go through that pain to end the lives of potential children?"
But at 24 with a new boyfriend, she got pregnant again and fantasized about motherhood, but he didn't want the baby.
"I felt like we were committing murder, that I was killing something that I wanted," said Mary. "I felt like I should feel the pain. I wanted to physically suffer."
After three abortions, she was left with lingering health problems and her doctor suggested she might not have a child again.
"When I was 21, it seemed easier," she said. "It was. It has a lot to do with my mental state about the situation. It feels like there is no healing for this."
Vilar, too, was warned by her doctor that she might never carry a child to term.
Women who have had multiple abortions face a potential risk for cervical damage and uterine lesions which can compromise future pregnancies, according to Dr. Louis Weinstein, chairman of the department of obstetrics and gynecology at Thomas Jefferson University Hospital in Philadelphia.