"Making Babies –
Advances make the impossible possible for parents"
From behind the broad desk in his elegant north Boulder office, fertility specialist Mark Bush has heard some lofty requests.
Parents of children with devastating hereditary disorders have come to ask what he could do to save their second-born from a similar fate. Parents with three boys have asked for help in conceiving the baby girl they've always dreamed of.
A decade ago, many of their requests would have gone unanswered. But today, with advances in reproductive technologies and human genetics progressing at a dizzying pace, doctors like Bush can screen developing embryos in a lab for a host of abnormalities, weeding out disorders like cystic fibrosis, Tay-Sachs disease, Down's syndrome, and muscular dystrophy long before the pregnancy test ever comes out positive.
"It is the ultimate form of preventive medicine," says Bush.
It is also one of the most controversial.
In the 12 years since preimplantation genetic diagnosis (PGD) was first used to screen embryos in a petri dish for cystic fibrosis, the technology has been expanded to detect dozens abnormalities, allowing parents undergoing in-vitro fertilization to choose only the healthiest prospects.
It has been used to screen out disorders that may show up later in life, such as early-onset Alzheimer's and certain forms of cancer. And a few parents -- including Linda and Jack Nash of Englewood -- have used it to assure their second child would make a good tissue or blood donor for a terminally ill first-born they are trying to save.
This year, Conceptions Women's Health and Fertility Specialists, the clinic Dr. Bush works for, became one of the first in the nation to take the use of PGD a step further, offering it to couples who want to "balance" the makeup of their family by pre-determining the sex of their next child.
Already, more than a dozen couples have signed up. Some need in-vitro fertilization anyway; some don't but are willing to undergo the hefty cost and complex medical procedures anyway to get the daughter or son they've always dreamed of.
"I know there is a lot of concern that this just the first step in boutique baby building, but I just don't see it that way," says a 43-year-old mother of one son, who will fly to the Colorado Conceptions office from her New England home to undergo PGD for gender selection. "We are not selecting on intelligence or eye color. We just want to have a daughter."
The latest uses of the technology have parenting chat rooms buzzing nationwide, and many local couples credit PGD for allowing them to have a child at all. But it has also sparked a firestorm of criticism as bioethicists, disability rights groups, and pro-life advocates ponder where the technology is taking us.
"At some point, if the cost comes down, the issue will become, 'What is the best way to make a baby? In the back seat of a car, or in a lab?,'" says bioethicist Arthur Caplan, chair of the department of medical ethics at the University of Pennsylvania. "These reproductive technologies could evolve into technologies that are used by fertile people to design their children."
How it works
On a recent morning at University of Health Sciences Center in Denver, embryologist Dawn Kelk peered through a high-powered microscope as she gently poked a tiny glass needle into the shell of a 3-day old, 8-celled embryo, tearing a microscopic hole in its side. Using a glass pipette, she then sucked out one cell, and spread the contents out on a glass slide.
Remarkably, amidst this tiny sample of microscopic goo, rested the answers to a host of questions a parent might want to ask: Did this particular embryo have all the right chromosomes in all the right places? Did it carry the gene for a devastating disease?
Was it a girl or a boy?
"If you know what the gene is, you can test for it," explains Kelk.
The embryo biopsy is far from the first step in PGD. First, the woman must inject herself for weeks with hormones that coax her body into producing extra eggs. Then, those eggs must be surgically extracted and fertilized with the male's sperm. Many of the growing embryos won't make it to day three. But when they do, they can biopsied and screened before a select one or two is implanted in the mother's womb.
Initially, the procedure was too medically complicated and costly to have broad appeal, doctors say. But as it has been refined and come down in price, its use has grown exponentially.
As of 2003, more than 3,000 cycles of PGD had been performed, and 700 children had been born as a product of the technology, according to the Journal of Medical Ethics.
At University of Colorado hospital, Kelk has helped many parents who have already had a child with chromosomal or genetic disorders assure the birth of a healthy second child. She has also helped a couple with a terminally ill child try to conceive a second whose blood type is a perfect match to save the life of the first.
But the hospital has drawn the line at using PGD for "family balancing."
"As a group, we have decided that's not something we are interested in. Just the message in general that one gender is better than another is unsettling to people," Kelk says. "If the potential is already there to select the sex of your child, we are not far from selecting the blonde-haired, blue-eyed child. Where do you stop?"
Drawing the line
The answers to that question -- even among past PGD patients -- are across the board.
Some clinics will offer PGD only to people who need in-vitro fertilization anyway. Others insist the couple must have medical need for PGD.
Carl, a 33-year-old Denver man, says he and his wife had no trouble getting pregnant. But they sought help from the Colorado Center for Reproductive Medicine, another Colorado clinic that uses PGD, after she suffered at least two painful miscarriages.
A test of the fetal tissue from one showed the presence of Trisomy 13, a chromosomal defect that often prompts miscarriage or, if the baby is carried to term, death in the first year of life.
Their choice: Try to get pregnant again naturally and hope for the best, or pay $15,000 for in-vitro fertilization and have the embryos screened.
Out of six embryos tested, only one was genetically normal.
Today, Carl and his wife have a "beautiful baby girl."
"Because my wife was at an advanced age, (in her late 30s), we knew she was more prone to chromosomal abnormalities," he says. "We would not want to have to find out later that we were having a child with one of those abnormalities and face the choice of whether or not to have an abortion."
When asked whether that same technology should be used to pre-determine the sex of a baby, however, Carl doesn't hesitate to answer: Absolutely not. "It takes another step in a direction that I don't want to see things go," he says.
Carrie Gordon Earll, senior policy analyst for bioethics at the Colorado Springs-based Focus on the Family, a conservative Christian organization, believes the technology has already been taken too far. She says she takes issue with any procedure that would lead to the knowing destruction of embryos, but she also opposes PGD for other, societal reasons.
She evokes images from pop culture films such as "Gattaca," a 1997 film in which parents use reproductive technologies to design their children down to the most minute detail, and says we aren't far off.
"This is genetic discrimination at its earliest stage," she says. "Our weaknesses and imperfections are part of what make us who we are and to try to make us some kind of super human race is really disturbing."
Bush, of Conceptions, balks at such concerns.
"We are doing nothing of the sort," he says.
In the vast majority of cases, he says, parents turn to PGD to avoid "lethal abnormalities." Even those who use PGD for sex selection, he says, often do it because they know they carry a genetic abnormality more likely to show up in one sex than the other.
"It is easy to proclaim for couples not to use this technology if your own children are healthy, but those are not the couples I am seeing," he says. "For us to turn out back on this technology and tell the couple to roll the dice and go away is unethical."
How soon parents could realistically custom-design their babies is unclear.
Today, embryologists have the capability to either test an embryo for a set of chromosomal abnormalities, Down syndrome among them, or for one particular genetic problem they are looking for.
"Nobody is doing a complete panel. It's not practical and the cost is totally prohibitive," says Kelk.
But some believe that technology is not far off.
Dr. William Schoolcraft, a Colorado physician who has been a leader in the field of in-vitro fertilization for decades, says research is already underway that could -- within a few years -- lead to the development of "microarray chips" that will allow doctors to screen embryo tissue for a broad array of potential genetic traits all in one shot.
"We could look at all 23 chromosomes and as many single gene defects as we wanted all at the same time," Schoolcraft says. But, he notes, the vast majority of the doctors in the field of reproductive medicine agree that the technology should be used sparingly. "If there were genes that could be identified that could lead to smarter or faster or more talented children, those are not the kinds of traits we will use this technology for."
The question now is: Will everyone use such restraint?
Bioethicist Caplan believes the answers should not be left entirely to those using, and profiting from, the technology:
"Here is a technology that is involved in making babies and it is, in my opinion, completely and utterly unregulated."
Caplan, who has been researching and writing about reproductive technologies for more than 20 years, takes care to steer clear of such sticky issues as when life begins and whether its ethical to dispose of embryos. But he does have concerns for the children being born out of PGD. What if the biopsy process somehow harms the embryo? Or what if a second child is born to save the first, and it doesn't work?
"We spent an awful lot of time talking about cloning. To me, that is a sideshow -- very few people are going to be interested in cloning," Caplan says.
PGD, on the other hand, could easily become quite common, particularly among the wealthy in the coming years. For what uses?
"That is the big looming ethical problem of the future. Yet no one seems to be willing to grapple with that as a matter of public policy," Caplan says.