Thoreau said that every child begins the world again.
Thoreau was right, of course. But he never had children of his own. He never spent nine months in the dark, wondering if his baby would be born whole, healthy, or at all.
But what was once a final verdict at childbirth has been transformed, in many cases, by a series of medical choices that can be made long before the first labor pains.
New York University's Dr. Jamie Grifo helped pioneer a technique that can prevent some childhood disorders before a child is born.
"I'm the luckiest guy in the world," Grifo told Smith. "This is the most incredible job. But it's incredibly difficult, too."
It's an offshoot of in-vitro fertilization called preimplantation genetic diagnosis, PGD.
"The idea behind PGD is, we know that certain couples carry genetic diseases. And for a couple who carries a genetic disease - mom and dad both have a bad gene, but they're healthy, a so-called recessive gene - 25 percent of their babies will have that terrible disease, for instance cystic fibrosis."
And so a couple undergoing PGD would have their embryos screened, with only the disease-free allowed to grow into a baby.
PGD can also flag disorders like Downs syndrome, muscular dystrophy, and many others.
So, can we build a better baby?
"Well, I don't think we really build babies," Grifo said. "But we can create an environment where we can get a healthier baby. And I think that's really our intent. That's what we try to do. We want couples to have healthy babies that don't have genetic problems, who have healthy, happy lives."
Americans have a long history in pursuit of more perfect progeny: Hospitals would hold beautiful baby competitions, and before World War I, state fairs would offer prizes for people who had what was thought to be the right stuff to make beautiful babies: A so-called "fitter family" contest.
"The idea was, in the words of the woman who started it, if we have people judging our cattle, why not have people judge our families as well?" said Wendy Kline, who teaches history at the University of Cincinnati.
Were they examined just like livestock?
"Yup - height, weight, ear size," said Kline.
"Why would people subject themselves to that?" Smith asked.
"Because what an honor! Wouldn't you want to be a model of what the future of America should look like?"
As proof of their genetic fitness, winners would get a medal, complete with a golden baby, proclaiming their "goodly heritage." The contests fell out of favor here during the 1930s, when a much more disturbing program of genetic screening began … in Nazi Germany.
Another offshoot of PGD: the embryos can also be screened for gender.
"Now we can choose the sex of the child with nearly 100 percent certainty," said Dr. Jeffrey Steinberg, who specializes in gender selection, a procedure that can cost up to $20,000.
His pitch is simple: If you're physically (and financially) qualified, you can choose the sex of your next baby. Steinberg's practice, with offices in Los Angeles and Las Vegas, is thriving.
"Is demand outweighing your ability to perform these procedures?" Smith asked.
"Demand, right now, outweighs supply," Steinberg said. "We're backed up about seven months to get in to be evaluated, to see if they qualify for the procedure. So there's a waiting list."
His ability to screen by sex does freak him out a little.
"We're not designing babies," Steinberg said. "What we're doing is we're letting nature do what she does normally, which is make boys and make girls. The only thing that we're doing is we're stepping in, and we're saying, 'Of the boys and of the girls, if this couple wants a girl, they're going to get only the girls.'"
"So you're helping Mother Nature along a bit?"
"Which is what all of medicine is. You know, if we left Mother Nature up to her own devices, everyone would die of appendicitis. And people don't die of appendicitis. So this is helping couples the same way that you would help someone if they walked into an emergency room with a bad appendix."