"Now you can design your own baby. But should you?" is the tantalizing teaser for this week's much-quoted article about preimplantation genetic diagnosis in the online magazine Slate. The inaccurate and sensational lead-in is entirely appropriate for the misleading, fear-mongering article.
I guess this is what happens when an article about advanced reproductive technologies falls into the hands of your chief political correspondent (William Saleton): the facts get completely lost in the spin.
Let's get one thing straight: You cannot "design" a baby. No technology exists to doctor an embryo to create desired traits, nor repair an embryo to correct genetic flaws. Preimplantation genetic diagnosis (PGD) is simply a screening test that provides genetic information about an existing embryo -- an embryo which has the exact same genetic makeup, inherited from its parents, as it would if it had been conceived at home in bed.
Saleton's scary article covers the "slippery slope" and eugenics bogeys, following the well-worn template laid down by other journalists who are equally ignorant of the basic facts about getting pregnant using IVF. (PGD testing can only be done as part of an IVF cycle.)
Putting the brakes on the slippery slope
First, we have hand-wringing over the injustice of screening embryos not just for devastating childhood illnesses, but even for manageable health problems that don't occur until later in life, or perhaps not at all.
...an American patient who plans to screen her embryos for an arthritis gene. The probability that the gene will cause the disease is only 20 percent, and if it does, the disease is highly manageable. Once you screen for one gene, it's tempting to screen for others.
The notion that parents shopping for the perfect baby can present a laundry list of potential diseases, and only accept embryos that match their stringent criteria, ignores a very basic fact of IVF life: in any IVF cycle, a woman can produce only a limited number of eggs, which become a fewer number of viable embryos. Couples don't cull embryos on a whim or a genetic propensity for hangnails, because an IVF cycle typically results in only a small number of embryos to choose from (and sometimes only one, or even none). Parents who screened out embryos with various trivial genetic flaws would quickly run out of embryos and go home with no baby at all.
Screening for a particular disease is not a frivolous matter. While some might downplay a disease by calling "manageable", it's another story for those who have seen firsthand the suffering it causes their own parents or close family members, perhaps seeing what awaits in their own future.
Saleton seems to think the woman screening for arthritis just thinks it's too inconvenient to keep a bottle of ibuprofen handy, but her form of arthritis
can cause fusion of the spine, may cause pain starting at 3 years of age, and has no treatment, other than painkillers and surgical joint replacement.
“My mother told me that the only worse thing than having cancer twice was having to give the gene to me.”
New York Times
But even if a woman could produce a hundred eggs in a cycle, in hopes of producing an embryo that meets a myriad of genetic requirements, PGD testing on a vast number of embryos for multiple conditions is simply infeasible. PGD is limited for several reasons: only one embryonic cell is available for testing, so only a few tests can be performed; analysis must be completed within 48 hours, because the embryo can't survive longer; and the cost is prohibitive. Adding multiple tests on dozens of embryos would send the normal PGD tab of around $3,000 soaring to maybe $30,000 or more, per cycle (on top of IVF costs).
So the only people in danger of sliding down this particular "slippery slope" are multi-millionaires with super-human egg producing powers.
Another patient ... set out to scan his embryos for colon cancer and ended up chucking two more for Down syndrome. "You kind of feel like you shouldn't be doing it," his wife confessed.
Saleton gives us the impression that, were it not for the villian of PGD, all of these "chucked" embryos would go on to lead happy, healthy, lives, more or less. But again, this conflicts with the reality of IVF: extra embryos are created, and some are discarded. A woman usually hopes to conceive exactly one baby, and no matter how many children she would love to have, she cannot safely incubate a litter of 5 or 6 at once.
With or without PGD, a couple in an IVF cycle who winds up with 10 embryos must choose, typically, one to three to implant, and must discard (or freeze, or donate) the rest. In a case where some embryos must be selected, and some must be discarded, PGD is simply a tool used to select the embryos most likely to result in a successful pregnancy and a healthy baby.
Without PGD, embryos are selected after being examined under a microscope, and graded for quality. The "most beautiful" embryos are the lucky ones selected for implantation. But, because even though the healthiest-looking embryo may harbor devastating chromosomal abnormalities and with zero chance of survival, choosing embryos by sight alone is only a little better than a wild ass guess.
How is it that it is somehow moral to choose embryos by inaccurately predicting their future health based on their 3rd day "beauty", but immoral to choose embryos by accurately predicting their future health based on genetic analysis?
Taking a swipe at savior siblings
Another oft-criticized use of PGD is to select an embryo because it is a tissue match for an existing sibling, and the resulting baby becomes a donor to cure the sibling.
Once you start treating a child as a tissue bank, it's hard to stop.
Last month, after a Swiss couple used PGD to pick a donor embryo for
their ailing son ... the donor infant, having failed to
provide enough cord blood, was subjected to a painful bone-marrow
extraction as well.
Certainly, any person would be outraged at the idea of a helpless infant being tortured like a lab rat in order to rob its tissues. But actually, bone marrow extraction is performed under anesthesia, and although there can be some soreness and pain afterward, it goes away and the body swiftly naturally replaces the lost marrow; in the scheme of things it doesn't seem an enormous price to save the life of another person.
The issue, presumably, is that no matter how the scales tip when weighing saving a life against a harmless procedure, the baby cannot consent to that procedure. How often, I wonder, do people who are actually asked to be a bone marrow donor, and are able to give their consent, instead refuse? We know that people volunteer quite willingly to be bone marrow donors
for perfect strangers, so it seems safe to assume that people usually step up to the plate when called upon by a family member. Certainly I wouldn't hesitate to be a donor even for my least favorite sibling. Second cousin, even. In a pinch I might even save a journalist.
Why then, would one assume on this baby's behalf, that rather than becoming a decent human being who would readily give his consent if he could, he will become a crass individual who would rather watch his sibling die than endure a few days with a sore hip?
Parents who seek to have a "savior sibling" have been vilified by the press as monsters looking to use a baby for spare parts. But if these people were really that heartless, they could easily choose a cheaper and easier route: just bury the first child and hop in bed and make a replacement. Instead, they have chosen a path that includes the exraordinary expense and inconvenience of IVF -- at a cost averaging $15,000 to $45,000, with no guarantee of a successful pregnancy. (And for those of us who know what it means to shed tears over an unsuccessful IVF cycle, try to imagine, for just a moment, what it must be like when a negative pregnancy test spells a death sentence.)
And beyond the birth of the savior sibling, there is still a matter of the bone marrow transplant for the ailing child, which involves a month-long stay in the hospital and perhaps a year of recovery. That is, if you're lucky, because there's a chance the transplant will be unsuccessful, and the child will die, or not be cured.
Why would anyone think that these parents, who are willing to go to such extraordinary lengths simply for the chance to save the life of a child, would view a second child as nothing more than a slab of meat? Wouldn't it be more reasonable to suspect that such parents would treasure a second child just as much as the first? More reasonable, perhaps, but not very sensational.