Behind Sarah Palin's very public persona as the former Republican vice presidential candidate, the self-described "hockey mom" from Wasilla, Alaska, is above all mother of five: Track, 20, who is in the Army and recently returned from Iraq; Bristol, 19, who gave birth to her son, Tripp, last December; Willow, 15; Piper, 8; and Trig, 19 months.
Of all the controversies and challenges that the former governor of Alaska has faced, none has been more personal than her unexpected pregnancy with a baby whom she learned had Down syndrome. In an interview to air on "20/20," Palin opened up to ABC News' Barbara Walters about son Trig and her concerns about the pregnancy.
Palin discovered she was pregnant with a fifth child while attending a conference in New Orleans in 2007. Then Alaska's first female and youngest governor at age 43, she said she was initially hesitant.
"For a fleeting thought, I knew what women go through when they're facing what they believe at the time are less than ideal circumstances," she said. "I never thought, do I want another child? What I did think for that split second was, Gee, now, of all times? And yeah, I'm no spring chicken."
After she returned to Alaska, a test revealed that Palin was carrying a baby with Down syndrome, a genetic condition that affects a child's intellectual and physical development. She said the moment gave her pause.
"I thought, 'God, unless you know more than I do about all this, how in the world would I handle this?'" she told Walters.
Ninety-two percent of women who get that news terminate the pregnancy, according to research reviewed by Dr. Brian Skotko, a pediatric geneticist at Children's Hospital Boston.
Palin said she knew abortion was an option but was able to overcome the fear of the unknown to go ahead with the birth.
"I knew that the option was there. ... I thought again, for that split second, 'OK, now I know, too, why, when that fear strikes you, because of the unknown,'" she said. "I understood then, too, why a woman would consider [abortion] an easier path to perhaps, if you will, do away with the problem, instead of understanding that every child has purpose. There is destiny for every child. And it can be good, in our world. And that's what I held onto."
When asked by Walters if her "right to life" stance on abortion dictated her choice, Palin said her decision was not "politically motivated."
"My decision certainly wasn't a political decision. It was a holding onto a seed of ...that promise that things will be okay if we choose life. And that certainly has come to fruition in my life," she said.
Although she "chose life," Palin said she and husband Todd struggled with how to tell the other children -- especially the two youngest, Piper and Willow, who both joined their mother for portions of the Barbara Walters interview.
"We didn't find out he had Down syndrome till the day he was born," Willow said. "So that was kind of a shock. But we didn't really care. He's still our brother."
When asked why she didn't tell the children earlier, Palin told Walters that she was not emotionally prepared to share the news with her family yet. Instead, she said, she wrote it all down in a letter, which she hadn't yet delivered when Trig was born.
"Trig came early ... about five weeks early, and I was thinking it would be in that last month that I would be prepared enough in my own heart to be able to share with my kids the preparation that was gonna be necessary," she said. "I had written a letter to family and friends ... hadn't delivered it yet, though."
Palin said she wrote the letter "as if it were the words of our creator."
Was it presumptuous to write a letter in the name of God?
"I would do it again in a heartbeat," she said. "I do think that it was the most loving way to express my belief that God doesn't make any mistakes, and that Trig would be in our eyes perfect for our family."
Palin's daughters Piper and Willow agreed, saying they sometimes took care of their new brother.
"We all pitch in," said Willow. "We love him. He's the center of our world."
About five thousand children like Trig are born with Down syndrome every year in the United States. All are mentally challenged to varying degrees. They may face retardation, delayed language and slow motor development. Half of the babies born with Down each year suffer from congenital heart defects; Trig has a hole in his heart that may require surgery. So far, Palin said he can walk, but he has vision problems and, at 19 months, doesn't eat solid foods.
It wasn't long ago that being a child with Down syndrome carried a stigma.
"Children were institutionalized by and large. They were separated from societies, from their families," said Dr. Susan Gross, a professor of obstetrics and gynecology at Albert Einstein College of Medicine and Chairperson of OB/GYN at North Bronx Healthcare Network. "There was a time that surgeons would perhaps not operate on a child with Down syndrome."
Walters opened up about her own sister with special needs, who was teased and called "retarded." Palin said some make fun of Trig.
"Some people have been quite cruel," Palin said. "I am on the Internet and ... [have seen] some horrible ads about him that he should have never been born. But, for the most part, people have been so loving and supportive of us that that encourages us and it makes us know that there is ... a lot of hope and there is a lot of love in this country."
Trig accompanied Palin for stints on the campaign trail, which prompted scrutiny. Many said she was exploiting her baby for a political end.
"Wasn't that something? You're kind of, you're damned if you do, damned if you don't," she told Walters. "But I'm very, very proud of my kids, including Trig, and I would do that again in a heartbeat... show the world that I'm proud of this diverse and full and very colorful family that I'm a part of."
Todd Palin joined his wife for portions of the Barbara Walters interview. He brought Trig along too.
Todd said that when his wife shared the news that their son would be born with Down syndrome, he knew his family could handle the challenge.
"I was very excited -- another baby in our family. And when she told me that our child might have Down syndrome, I asked myself, I just, I said, 'Why not us? Our family is never one to have that, you know ...want anybody to feel sorry for us,'' he said. "I knew that our family was strong and would be able to handle whatever was thrown at us."
Todd, 45, a former snowmobile champion who worked on the oil fields of Alaska's North Slope, said that Trig will be able to keep up with his family's outdoorsy lifestyle.
"He'll be able to do everything that our -- that all of our other children have done with us," Todd said. "We treat him just as another kid in the house and I look forward to getting him out on the trail this winter."
So, what's the biggest misconception about children with Down syndrome?
"They are just beautiful gifts from God for all of us to learn from ... and to make us stronger as we live," Todd Palin said. "He is just another kid in our house. ... But he has, but he has just been a blast."
Given medical advances and much-improved educational approaches, Trig should grow into a productive member of society.
"At the turn of the last century a child like Trig would have been lucky to perhaps even to make it to 10 years of age," said Gross. "You could easily say 60 years of age now."
Walters also asked Palin if she wants to add more children to the brood.
"I'll stick with the grandkids thing now, but even that can wait another ten years, as Bristol would tell you," Palin joked. "Ten years from now? Oh gosh, bring on the grandkids. I can't wait."
At age 17, Bristol Palin surprised the nation when her pregnancy was announced in September 2008. Bristol gave birth to Tripp Easton Mitchell in December. Bristol and Tripp's father, 19-year-old Levi Johnston, called off their engagement soon after their son was born.
Since then, the relationship between Johnston and Palin has become severely strained, escalating into a full-blown war of words in the media. Johnston accused Palin of being a neglectful and insensitive mother and claimed she called Trig "the retarded baby," among other jabs.
"That's heartbreaking to know that he would say such a thing ... and that's not true," Palin told Walters.
Johnston has also alleged that the Palins are on the verge of divorce -- accusations that Palin denied to Walters.
"Todd and I have been together -- he was 16, I was 17 -- for many, many years. We've been married many, many happy years, and we remain a solid, happy, blessed couple," she said.
Johnston has claimed that he will sue for joint custody of their 11-month-old son -- a move that Palin said she would applaud.
"Well, it will be nice to see, in -- I guess -- even in legal proceedings, a desire to be a part of the baby's life," she said. "That's a good sign."
Johnston has said that Palin was wise not to speak ill of him in her best-selling memoir, "Going Rogue: An American Life," because, "she knows what I got on her."
"He doesn't have anything on me," Palin told Walters.
Johnston has catapulted himself into the media spotlight, posing for Playgirl magazine last week and making public appearances. When asked if Johnston had contributed any of his profits to child support, Palin demurred.
"Levi's making some irresponsible decisions right now with money, and with career. I guess his handlers are sort of ushering him into this new line of work, with the porn, and with the things that he's involved in right now. He's a kid who's misguided, and he's kind of lost right now," she said.
Despite the crossfire, Palin seemed to suggest that he would always have a place in the family.
"I'm going to leave it at that, acknowledging that he will always be a part of our family. I can't wait until he comes back on that right road of wanting to be a part of the family in Tripp's life. It's going to be good. At the end of the day, this will be a good experience," she said.
The 2008 Republican vice presidential nominee opened up about the controversial campaign and told Walters that her life "has become a kind of a reality show."
But the public just can't seem to get enough of all things Palin. Her "Going Rogue" book tour rolled into Michigan this week. A spokeswoman for Harper Collins, Palin's publisher, told ABC News that book sales have been so strong that they've had to run more printings -- 2.5 million copies of "Going Rogue" had been printed as of midday Friday.
Despite all the adulation, this woman from the top of the world says she knows where she'd rather be.
"A perfectly happy day would be in my home, with all of my children there, and Todd," she said. "A wonderfully beautiful Alaskan day, where we're outside running, and enjoying all that is Alaska, and then we get to come in and enjoy one another's company -- with a bowl of moose chili."