It sounds like science fiction. A scientist surveys a new human embryo, extracts one of its cells, amplifies its DNA, and screens it for mutations. When the scientist finds the DNA that appears to be mutation-free, the embryo is implanted into a woman’s uterus. And voilà. A healthy, heritable-disease-free baby.
It’s called embryo screening.
Having a say in a pregnancy’s outcome is not a new concept. Old wives’ tales taught that if you eat a lot of salt you’re more likely to give birth to a boy, but eat a lot of dairy products and you’re more likely to have a girl. Other theories claimed that if you used the right position while trying to conceive, or tried to conceive at the right time of a woman’s cycle, you could favour one sex over the other.
And once you had conceived, you could predict the unborn child’s sex by swinging a needle on a thread over the palm of the mother’s hand. Swinging back and forth? It’s a girl. Spinning in a circle? It’s a boy.
Needless to say, conceiving children and determining their sex before birth has come a long way since then. The first new science was artificial insemination, i.e. impregnating a woman with donated sperm. The sperm is frozen, thawed when it’s called to do its duty, and eventually inserted into the woman’s cervix or uterus using a catheter.
Artificial insemination was first successfully performed on farm animals in Russia in 1899. The first human artificial inseminations were experiments in the Nazi concentration camps during World War II. Records do not indicate whether or not successful births resulted.
Then came in vitro fertilization. In vitro, Latin for “in glass”, is fertilization done in a test tube. First, the woman’s ovulation is hormonally controlled to find the optimal time for extracting eggs from her ovaries. Next, scientists fertilize the egg cells with sperm. Finally, they implant the embryo into the mother’s uterus. IVFs were first successfully done in England in 1973.
Today’s even newer science is a combination of IVF followed by embryo screening.
Is this “unnatural selection”? Yes, in a manner of speaking. Is it wrong? That’s harder to answer.
Some people, especially religious groups, condemn the developing science as “playing God” or interfering with how a baby is allegedly supposed to develop. Some scientists, however, applaud it. They argue that a parent’s goal in any species (according to the laws of evolution) is to improve the species as much as possible, and that that should be our goal, too.
Scientists are already helping parents screen embryos to “design” their future baby with the least likelihood of inheriting disease. At least, that was the initial goal.
The birth of embryo testing was in a London hospital in 1989. Its aims were noble: to eradicate hereditary diseases like muscular dystrophy, cystic fibrosis, and Tay-Sachs disease. In each case, the disease was attributable to identifiable parts of the genetics. Simple, right? Look for the mutations in the embryo’s DNA and make sure you don’t pick them.
Soon, however, this goal evolved into the pursuit of the so-called “designer baby”. Soon parents, at least half of whom were perfectly fertile, were flooding the scientists’ phone lines with questions about eye colour, height, and intelligence.
Could you make her pretty? Can she get my teeth? My family really wants it to be a boy. Can you make him really smart? One famous singer asked if her baby would inherit her vocal talents. A sports star asked if his baby could be tall.
Can he be superman?
In Canada, the Supreme Court still prohibits selecting a child’s sex. Some Canadian parents travel to genetic engineering labs in Mexico for the expensive treatments.
What may seem surprising in all of this is how quickly genetic engineering has developed. People are so eager to create the perfect child, although the science itself—a science still in its infancy compared to many others—needs to work out all the kinks.
For example, consider Megan and Morag.
Megan and Morag, two little-known sheep in Scotland, were the first mammals successfully cloned from embryonic cells in 1995. Strangely, they did not nearly garner the same international attention, nor fuel the same fierce debate, as did the cloned lamb Dolly a year later. With Dolly, the world asked: What are the health implications of the clone? Can she live as normal a life as her natural brothers and sisters? Can we do this with humans? Should we?
Scientists at the Roslin Institute in Edinburgh, Scotland, cloned all three animals. The scientists proudly declared that all three animals were healthy, with Morag giving birth to a healthy lamb 18 months after her own birth. But the scientists don’t claim that Megan and Morag happened easily.
The two genetically identical sheep were the only two survivors of many more genetically identical fetuses. Two lambs died within minutes of birth and a third died 10 days later. Then there were the karyoplasts (nuclei with a plasma membrane and a bit of cytoplasm—just in case that helped) that did not develop into embryos, the foetuses that did not come to term and died, and the complication with Dolly.
Dolly died prematurely, at six and a half years old, in 2003. Sheep like Dolly live for 11 to 12 years on average. Post-mortem analyses of Dolly showed that she had developed a progressive lung disease. She also suffered from arthritis, which usually does not develop in her species until much later in life.
Dolly’s early death fanned the flames once more in the scientific community concerning the health of genetically engineered mammals.
Of course, there have been countless success stories, including icons like Celine Dion, who recently gave birth to healthy twin boys via in vitro fertilization. What is less publicized is that before she had her twins, Dion lost four children to IVF.
These kinds of losses pile another huge ethical question on top of the first one.
“I was enamoured by the science,” said Dr. Jeffrey Nisker, a Canadian researcher working on genetic engineering of embryos. “But, you know, I had never really thought about where it was going.”
As parents continue to sign up for embryo screening, many scientists continue to give them what they want.
“I don’t see myself as a rebel,” said Dr. Steinberg, a leading scientist in the screening of embryos. “I’m just offering what the science allows.”