How ‘flawed’ is too flawed for IVF embryos?

Soupcoff, A9

In the movie Juno, the title character tells a couple who have been having trouble adopting a child that they should have gone to China. “They give away babies (there) like free iPods,” Juno says. “They put them in guns and shoot them out at sporting events.”

As anyone who has struggled with fertility and adoption knows, Juno’s sarcastic, culturally insensitive, and outrageously funny comment isn’t even accurate. (Though as anyone who has seen Juno knows, Juno is smart enough to know this herself.) It’s not easy to adopt a baby from China. It’s not easy to adopt a baby. Sometimes it’s not easy to get pregnant, even with the incredible advances in assisted reproductive technology.

Many would-be parents want a child so much that they would gladly try treatments and procedures with poor or unclear odds; and why shouldn’t they, as long as they’re fully informed? Not a question being asked a lot yet. But it will be.

Indeed, thanks to new testing that can identify “mosaic” embryos during an active cycle of in vitro fertilization (IVF), it’s a question we’d better sort out sooner rather than later, because it’s an important one to get right. The answer will decide who gets to choose which embryos are too “flawed” to be worthy of a chance at becoming a human being.

Mosaic embryos are embryos that have a mix of normal and abnormal cells. When used in IVF, mosaic embryos can implant successfully in a patient’s uterine wall and develop into healthy fetuses that become fully formed healthy babies … but they are less likely to do so than embryos containing only normal cells.

Mosaic embryos have a greater chance of becoming fetuses that are miscarried; they may have a greater chance of becoming infants with birth defects. But exactly what those chances are, scientists don’t yet know.

The thing is, for any human being to choose the level of genetic perfection required of a potential baby is somewhat creepy. I don’t mean we don’t already do it. We do it all the time, including when we test for Down syndrome and neural tube defects during

pregnancy, with the expectation that the mother will consider terminating her pregnancy if a defect is discovered.

I mean it’s uncomfortable to talk about choosing the required level of genetic perfection because it’s an awesome power we may not be wise enough to handle sagely. Or trust others to handle sagely — which probably is to say, the way we would.

It’s a bigger deal with mosaic embryos, though, because the choice doesn’t automatically default to the parent, the way it does during a pregnancy.

No one can make a pregnant woman abort a fetus because of a genetic defect. But it’s entirely possible that legislators and/or reproductive endocrinologists could decide to disallow transferring mosaic embryos altogether, even to well-informed women who want them despite the risks.

Richard Scott, founder and laboratory director at Reproductive Medicine Associates of New Jersey, told The New York Times in 2016, “Every research program is fearful of throwing away a healthy embryo, but on the other hand, mosaicism is not always a benign thing.” He continued, “Now we are paying attention to these mosaics, but we don’t know exactly what to do with them.” Several more mosaic embryo transfers have resulted in the birth of healthy babies in the two years following the article.

Scott’s honesty is refreshing; so many experts and policymakers refuse to admit that they don’t have all the answers. They are the ones with the potential to lay down brittle rules about discarding mosaics — rules that may not serve potential parents, or even the moral or ethical norms we want for our society.

The average would-be parent is no position to assess the risks and odds for a mosaic embryo; they depend on their reproductive endocrinologists and/or geneticists for that. But once the risks and odds have been explained, the average would-be parent is in, if not a good position to choose what to do, then at least in a better position than anyone else.

Science has brought us to the point where some mere mortal is going to have to decide how normal a potential human being must be, to be considered worthwhile. Who should that mortal be? An expert? Or the parents who are sacrificing to bring a new human being into the world because they want more than anything to share their nurturing, care and love?