(NEW YORK) -- Spend 10 minutes on the phone with Dr. Susan Robinson, an obstetrician-gynecologist who specializes in providing women with third-trimester abortions, and the name Aron Ralston will invariably come up. He's the mountain climber who was trapped in a canyon in Utah after a boulder crushed his right hand. He was pinned down by the boulder for five days (the film 127 Hours is based on his story) until he realized the only way he could get free would be to cut off his hand.
It's a graphic, horrific image, but Robinson says it's the best analogy she can think of to describe women who are pregnant in their third trimester and "have thought about it deeply, consulted their conscience, wrestled with the ethics, and decided the best thing for themselves and their families is to have an abortion."
"People think you choose an abortion like you choose red or green shoes, or a flavor of ice cream," Robinson told ABC News. "But in fact, they [the women I see] need an abortion the way Aron Ralston needed to cut his hand off."
Robinson is one of four doctors featured in the documentary After Tiller, which screened at the Sundance Film Festival this past weekend.
The film takes its name from Dr. George Tiller, a third-trimester abortion provider in Wichita, Kan., who was assassinated in May 2009 while attending church. Robinson worked with Tiller, as did Shelley Sella, who worked as a midwife before becoming a doctor and abortion provider, and is also featured in the film. The two now operate out of a clinic in Albuquerque, N.M.
"We learned at his knee," said Robinson, speaking of Tiller. "Kindness, courtesy, justice, love and respect are the hallmarks of a good doctor-patient relationship. People tell me every single day, 'Dr. Robinson, you've given me my life back.' For these women it is life or death. Many women try to self-abort. The less available it is, the poor will have the hardest time."
If abortion is a hot-button political issue, then third-trimester abortion is red-hot, and such words as "kindness" and "respect" are not two that leap to mind for many people. The arrest two years ago of Philadelphia doctor Kermit Gosnell, accused of killing a woman with a lethal dose of Demerol, put a gruesome face on doctors performing third-trimester abortions. Police, searching his office, found what prosecutors called "a house of horrors" -- bags and bottles of aborted fetuses scattered throughout the building, a place where fetuses were delivered live and then killed with scissors.
Even many supporters of abortion rights draw a line at third-trimester abortions. A 2011 Gallup poll showed that making abortion illegal in the last trimester got strong support from both pro-choice (79 percent) and pro-life advocates (94 percent).
Laws passed in 41 states prohibit abortions, except to protect the woman's life, after a certain point in the pregnancy, usually fetal viability (about 24 weeks). In the U.S., 88 percent of abortions are done in the first 12 weeks, according to the Guttmacher Institute; fewer than 1 percent are in the third trimester.
Dr. Lauren Streicher, an assistant clinical professor of obstetrics and gynecology at Northwestern University's medical school, does not provide third-trimester abortions but said, "In my career, there have been times when I've had to tell women this desperately-desired pregnancy has not gone well. These are babies that have congenital abnormalities that are incompatible with life -- no hope, no brain, no kidneys, something that is not surgically fixable."
In an academic, urban center, Streicher says she can refer her patients to doctors at a family planning clinic who do provide third-trimester abortions, but are not as public as the four doctors in After Tiller, whose patients often find them via the Internet and who need financial help from organizations such as the National Abortion Federation.
Women whose fetuses have terrible abnormalities, Robinson said, "are a lot easier for people to understand. The husband and wife want to spare their baby whatever suffering that baby would have."
"Then there's the group of women who didn't know they were pregnant," she said. "They were told they were not pregnant for one reason or another and they are just as desperate. 'I already have three children, my husband just lost his job and I can barely put food on the table. If I add a new baby to this family, we'll all go under.'"
After Tiller follows the four doctors past the anti-abortion protesters who regularly stand outside their clinics. It shows Drs. Robinson and Sella in Albuquerque; Dr. Warren Hern in Boulder, Colo.; and it shows Germantown, Md., where LeRoy Carhart recently set up a practice.
The camera never shows the faces of the patients, but instead shows hands fidgeting in laps, boxes of tissues being consumed, voices quaking and lots of crying.
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