March 5, 2015 -- Babies created from the DNA of two women and a man could be born as early as next year. Last month, the United Kingdom cleared the way for fertility clinics there to start making babies using three-parent in vitro fertilization (IVF) beginning in October.
The landmark decision has sparked hot debate. Some say it will help save babies' lives. Others believe it's an ethical dilemma that opens the door for "made-to-order" kids.
Here, two experts answer some commonly asked questions.
What Is 3-Parent IVF?
It's a fertility treatment that creates an embryo using the genetic (DNA) material from three people: the parents and an egg donor.
During normal conception, a fertilized egg has a mix of nuclear DNA from both parents. That DNA contains most of a person’s genes and all the genes responsible for a person's traits. The egg has the exact copy of mitochondrial DNA from the mom. This DNA powers every cell in the body and helps them divide and grow.
If the mom's mitochondrial DNA is defective, it can cause severe or deadly disease in the baby.
But what if you could remove the mom's faulty mitochondria and replace it with a healthy kind? That's exactly what three-parent IVF does. It's also called mitochondria donation. There are several techniques available, but in general, the nuclear DNA from the mom's egg is replaced with healthy mitochondrial DNA from an egg donor.
"It is like a tiny transplant," says Arthur Caplan, PhD, founding director of the Division of Medical Ethics at NYU Langone Medical Center. He finds the term "three-parent IVF" misleading. "It is more like two and .00001 percent parenting. The amount of mitochondria transferred is trivial. It doesn't give that person any parenting claim."
Who Will It Help?
Right now, three-person IVF is for women who have a rare defect in their mitochondrial DNA. (Genetic testing can check for it.) These women often have miscarriages or stillbirths. A baby born to them will have incurable mitochondrial disease. The disease often has devastating impacts on the heart, liver, and other organs. The child may live only a short time after birth. Most do not live to adulthood.
Researchers have estimated that about 1 in 4,000 children are born in the U.S. each year with some kind of mitochondrial disease.
Until now, the only fertility options for such women have been IVF using an egg donor or adoption. Three-parent IVF instead gives these women a chance to have a healthy, genetically related child. Supporters of the technique say it also prevents mitochondrial defects from being passed down to future generations.
What Are the Concerns?
Opponents say changing the genetic material in an embryo could give rise to "designer babies," kids whose eye color or other traits are hand-picked by their parents before birth. They question whether it's safe or worry that the parent-donor DNA won't mix well.
"The controversy is that a foreign type of DNA could lead to long-term birth defects of its own or other complications," says William Schoolcraft, MD, director of the Colorado Center for Reproductive Medicine. "But there is enough data to say it likely seems safe."
Others say three-parent IVF is about saving babies; it's not about creating "super-kids" (a concept called eugenics).
"It's a myth that three-parent IVF is the road to eugenics," Caplan says. "It's a gene transplant. You're not going to make a taller, stronger baby from this technique. You'll make a live one instead of a dead one."
Is It Available in the U.S.?
Not yet. "That's causing some confusion," Schoolcraft says. "I've already had patients call me asking about it."
But the FDA is looking into it. It has asked the Institute of Medicine to look into the safety and ethical issues. (Meetings are scheduled for later this year.)
The American Society for Reproductive Medicine says in a message to the FDA: "We believe the science behind oocyte [egg] manipulation to transfer mitochondria is interesting and has promise in treating infertility and preventing the transmission of mitochondrial disease."
Caplan says: "Every IVF clinic in the U.S. is ready to go with it. I would expect it to move quickly."