"All [mothers] described moments of shock, grief and sadness," he told ABCNews.com. "The majority expressed disappointment in the way that their physicians delivered the news."
But, he said, nearly all those families eventually "learn the joys of having such a child."
In his case, his sister taught him many of life's lessons. "When others mock, she teaches me to stand up and defend myself," he said. "I see how hard she works, and it makes me more determined to work."
Skotko said parents need to know that their children can lead "full and productive lives." His sister now lives in Ohio and works two jobs and has a boyfriend.
Still, there are challenges. About half of the children born with Down syndrome have cardiac deformities, but most of those can now be repaired. With medical advances, they can expect to live until well into their 50s or 60s.
Studies also show that siblings of children with Down syndrome are more empathetic and caregiving than others.
Will Drinker, 22, is chronicling his older brother Dan's life on video: his first date, dealing with death and even his YouTube endorsement of Barack Obama. Together they have created the Web site dandrinker.com.
Despite Down syndrome, Dan Drinker holds down two jobs -- as a bagger at Acme and working at a center that provides services for those with developmental disabilities.
Dan's worth is unquestioned in the Drinker family. To date he has saved two lives: a younger sister who nearly drowned in a pool and a suicide jumper who fell into the water near Dan's boat.
"One of the elements of the project is attempting to save Dan," Drinker told ABCNews.com. "This is a historic document. This thing we know as Down syndrome will probably be a bygone era."
Doctors like Skotko agree that when it comes to ending a pregnancy, doctors must "respect the wishes of patients," but say that many at home are misinformed.
He said an estimated 80 percent to 90 percent of all mothers believed caring for a Down syndrome child would be "too severe, that they would be sad all the time and would be a burden to the family."
That was the case with Deirdre Featherstone, a New York City jeweler, who had scheduled amniocentesis when she became pregnant at the age of 37 but then canceled it.
"One of my theories is that certain things are meant to be," Featherstone told ABCNews.com.
But she still worried. "Having a baby is a huge commitment," she said. "It's the only thing you can't get out of, like divorcing your husband or moving or selling your car."
"As I went through my pregnancy I became more in touch with the gravity of being a parent," Featherstone said. "I don't want life to be any harder than it is. I'm not carrying a special needs child full-term."
When she delivered the baby at home in 1998, the midwife noticed the classic low muscle tone, facial features and genetic bend on its finger. The baby was diagnosed with Down syndrome.
"To be honest, it wasn't what I was expecting," she said. "But I felt two things: She was the nicest human being I had ever met and whatever it took, it didn't matter. I was in it for the long haul."
Featherstone is fairly certain she would have taken the new Sequenom test had she been offered it early in her pregnancy. But now, with her 9-year-old daughter, Catherine, who brings much joy to her life, she is glad she didn't have that opportunity.
"She's a riot," said Featherstone. "She is so evolved in some areas and in others not so. But she is always raising awareness of the things closest to the truth. She has so much more clarity that those of us who are more socialized."