Parenting of the future: Many embryos, each with DNA profile (Update)

April 18, 2018 by Malcolm Ritter
Ethicist foresees choosing your baby from dozens of embryos
This undated microscope image provided by the American Society for Reproductive Medicine in January 2018 shows a trophectoderm biopsy, in which cells from the outer layer of an embryo that develop into the placenta and amniotic membranes are removed and can be used for genetic testing. When a couple is known to be at risk for having a child with a specific genetic disorder, the woman undergoes a procedure to remove some of her eggs. After fertilization, some cells can be plucked from the embryos and examined to identify those without carry the disease-causing abnormality. (ASRM via AP)Wedn

So you want to have a baby.

Would you like a dark-haired girl with a high risk of someday getting colon cancer, but a good chance of above-average music ability?

Or would you prefer a girl with a good prospect for high SAT scores and a good shot at being athletic, but who also is likely to run an above-average risk of bipolar disorder and lupus as an adult?

How about a boy with a good shot at having musical ability and dodging asthma, but who also would be predisposed to cataracts and type 2 diabetes?

Confused? You're just getting started. There are dozens more choices for which of your embryos should be placed in the womb to become your child.

That's the future a biomedical ethics expert envisions for 20 to 40 years from now—soon enough that today's children may face it when they start their own families.

"The majority of babies of people who have good health coverage will be conceived this way," predicts Henry Greely, a Stanford University law professor who works in bioethics.

You've probably read about concerns over "designer babies," whose DNA is shaped by gene editing. Greely is focused on a different technology that has gotten much less attention: In a startling bit of biological alchemy, scientists have shown that in mice, they can turn ordinary cells into sperm and eggs.

It's too soon to know if it could be done in people. But if it can, it could become a powerful infertility treatment, permitting genetic parenthood for people who can't make their own sperm or eggs.

It also would mean that a woman who wants to get pregnant could produce dozens more eggs per attempt than with the current procedure of harvesting some from her ovaries.

And that means a lot of choices.

___

AN ARRAY OF EMBRYOS

Here's what Greely envisions: A man and woman walk into a fertility clinic. The man drops off some sperm. The woman leaves some skin cells, which are turned into eggs and fertilized with the man's sperm.

Unlike in vitro fertilization today, which typically yields around eight eggs per try, the new method could result in 100 embryos.

The embryos' complete library of DNA would be decoded and analyzed to reveal genetic predispositions, both for disease and personal traits. The man and woman would get dossiers on the embryos that pass minimum tests for suitability.

Out of, say, 80 suitable embryos, the couple would then choose one or two to implant.

The possibilities don't stop there. The technology might also help open the door to same-sex couples having children genetically related to both of them, though the additional twist of making eggs from men or sperm from women would be a huge biological challenge.

More worrisome is the so-called Brad Pitt scenario: We all shed a bit of sloughed-off DNA every day, like on the lip of a coffee cup. Such discarded material could be secretly snatched up to turn an unwitting celebrity into a genetic parent.

It is a long way in the future, but real life is already creeping toward it. Some scientists are trying to make human eggs and sperm in the lab. They are working with "iPS cells," which are ordinary body cells that have been morphed into a malleable state.

Amander Clark of the University of California, Los Angeles, says her goal is to aid basic research into why some people are infertile. She acknowledges the technique might itself be used to treat some infertility, particularly in young people made sterile by cancer treatments.

As for decoding the complete DNA library of embryos, Dr. Louanne Hudgins, who studies prenatal genetic screening and diagnosis at Stanford, says some pregnant patients there say they've already had fertility clinics do that. They didn't reveal why, Hudgins said.

Hudgins, who's president of the American College of Medical Genetics and Genomics, said no national medical association has endorsed decoding all the DNA of a fetus, which is called its genome. So she believes no insurance company would pay for that now.

___

'EASY' PRENATAL DIAGNOSIS

Greely, who lays out his ideas in a book called "The End of Sex and the Future of Human Reproduction," calls his vision "easy PGD," or prenatal genetic diagnosis.

Ordinary PGD has been done for decades. When a couple is known to be at risk for having a child with a specific genetic disorder, such as cystic fibrosis or sickle cell anemia, the woman undergoes a procedure to remove some eggs. After fertilization, some cells are plucked from the embryos and examined to identify those without carry the disease-causing abnormality.

That procedure looks for a specific problem in a few embryos, not entire genomes from dozens of them. If a couple wants to select a "super baby," says Dr. Richard Scott Jr., a founding partner of Reproductive Medicine Associates of New Jersey, "we tell them we can't do it."

In fact, Scott and others say, even wide-ranging analysis would not provide a precise forecast of how a child will turn out.

If DNA is the hardware, there's also the software: chemical modifications that determine when and where particular genes turn on and off. Much of this "epigenome" would develop after an embryo's genes are sampled, Scott said.

"Your child may not turn out to be the three-sport All-American at Stanford," because "the epigenome didn't work out," Scott said.

Greely agrees that predictions about behavioral traits like intelligence and athletic ability will be imprecise, because of epigenetics and because of basic uncertainties about what genes are involved and how they interact. And a person's upbringing and life experiences have a big effect.

___

WHAT WOULD COUPLES DO?

Even if the predictions aren't perfect, would couples want to take steps to control their child's genetics? Many experts doubt it.

Only a "very small minority" seek a perfect baby, says Stanford's Hudgins. In her practice, she said she often finds women pass up all screening because they figure the baby's fate is "in God's hands."

Dr. James Grifo of the New York University Fertility Center also questions how popular the idea would be.

"No patient has ever came to me and said, 'I want a designer baby,'" said Grifo, who's performed in vitro fertilization since 1988.

Greely doubts that influencing brainpower or athleticism would be a major draw for parents. Instead, he thinks they would care most about avoiding awful diseases that strike in infancy or childhood. They'll probably be less concerned about illnesses that might show up later in life, such as Alzheimer's or Parkinson's. For one thing, he says, parents-to-be may see them as becoming treatable by the time a child becomes vulnerable.

He thinks easy PGD is coming, and it would be better if properly handled. He says it should be proven safe, subsidized, monitored for long-term effects, and regulated so that parents can choose whether to use it and decide what embryonic traits to focus on. And he'd outlaw stealing somebody's DNA and unwittingly making them a parent.

___

OTHERS SEE PITFALLS

Once the genetic profile is done, could it come back to haunt a child if, say, a life insurer or nursing home demanded to see it to assess disease risk? How would the large number of rejected embryos be handled ethically and politically?

Perhaps future regulation could limit the number of embryos created, as well as what traits a couple could select for, said I. Glenn Cohen, a Harvard law professor.

Lori B. Andrews, a professor at the Chicago-Kent College of Law, summed up her views in a review of Greely's book.

"The idea of easy PGD," she wrote, "should make us uneasy indeed."

Still, even some who doubt the idea's feasibility say Greely is right to raise the issue.

"It's certainly something we have to take seriously and think through now," said Marcy Darnovsky, who writes on the politics of human biotechnology as executive director of the Center for Genetics and Society in Berkeley, California. "This is not just a technical or science question."

Explore further: Changes in human reproduction raise legal, ethical issues, expert says

Related Stories

Changes in human reproduction raise legal, ethical issues, expert says

April 7, 2016
What if prospective parents were given the opportunity to make decisions ahead of time about the combination of genetic traits their child would inherit?

Research on mice suggests new fertility treatments

October 4, 2012
Japanese scientists have turned mouse skin cells into eggs that produced baby mice—a technique that, if successfully applied to humans, could someday allow women to stop worrying about the ticking of their biological clocks ...

In US first, scientists edit genes of human embryos (Update)

July 27, 2017
For the first time in the United States, scientists have edited the genes of human embryos, a controversial step toward someday helping babies avoid inherited diseases.

US woman delivers baby from embryo frozen for 24 years

December 21, 2017
An American woman has given birth to a healthy baby girl from an embryo that was frozen a quarter century ago, in what hospital officials say may be a world record.

Dutch medical centre probes suspected IVF sperm mix-up

December 27, 2016
A Dutch medical institution announced an investigation Tuesday after discovering that up to 26 women may have been fertilised by the wrong sperm cells at its IVF treatment laboratory.

Recommended for you

Research could help conception in IVF patients

September 26, 2018
A study of the way mouse embryos attach to the womb may one day lead to an improvement in the conception rates of women having IVF.

Undiagnosed STIs can increase negative PMS symptoms

September 17, 2018
Women that have undiagnosed sexually transmitted infections may be at greater risk of experiencing negative premenstrual symptoms (PMS), according to new Oxford University research.

High dose folic acid does not prevent pre-eclampsia in high risk women

September 13, 2018
Taking high dose folic acid supplements in later pregnancy (beyond the first trimester) does not prevent pre-eclampsia in women at high risk for this condition, finds a randomised controlled trial published by The BMJ today.

Study finds air purifiers may benefit fetal growth

September 12, 2018
A new study led by SFU health sciences researchers Prabjit Barn and Ryan Allen reveals fetal growth may improve if pregnant women use portable air purifiers inside their homes.

Delayed childbearing is a growing source of multiple births, study shows

September 12, 2018
Starting in the 1980s, the number of multiple births—twins, triplets, quadruplets and quintuplets—steadily increased from about 20 sets per 1,000 live births to almost 35 sets per 1,000 live births in the 2010s.

Transforming pregnancy research with a smartphone app

September 5, 2018
For years, pregnant women have been underrepresented in biomedical research. Current treatments, interventions and guidelines do a poor job of taking into consideration the diverse characteristics of all pregnant women.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.