Three parent embryos, that is, embryos with three genetic parents…wait a minute…how can a child have three genetic parents?…what does this mean? The technology is not new, it’s been around for years. What is new is that the British government voted last week to allow this type method to be used on human embryos.
Reading the comments and the letters to the editor in the Telegraph (UK newspaper), you can see the arguments going back and forth: one side says this is a “playing God” while the other side accuses Christians of being “uncaring” towards childless parents or ignorant of science. To (hopefully) clarify things a little, I’ll explain what one of these three embryo processes entails.
The first thing to understand is that in the area surrounding the nucleus of an embryo exists what is called mitochondrial DNA. We’ve long been told that our DNA comes from our mother and our father and that all the genetic material needed to create you was contained in the sperm and the ovum. But there’s more than just the genetic material in the nucleus; we now know that the mitochondrial DNA in the embryo directly affects the DNA in the nucleus, thus, if unhealthy mitochondria is present, then genetic diseases or birth defects will be passed into the nucleus DNA.
So, what’s the technique for creating three parent embryos and why all the brouhaha? You start with the parents’ embryo that has unhealthy mitochondria. In parallel, you get a donor embryo with healthy mitochondria. Obviously, these are all created via in vitro fertilization (IVF), which presents it own set of ethical issues—such as creating more than you need and leaving some in frozen storage (cryopreservation), or rejecting embryos based on a pre-implantation genetic diagnosis that points to a genetic disease being present, or tossing out the embryo that is the “wrong” sex.
In step 2, you remove the nucleus from the parents’ embryo as well as removing the nucleus from the donor embryo. The donor embryo nucleus is destroyed (i.e., killed—a human life is ended). In step 3, you put the parents’ nucleus into the donor’s denucleated embryo. The nucleus continues to develop and you (hopefully) get a healthy baby.
Here’s a simple graphic from the Human Fertilisation and Embryology Authority that shows one way that a three parent embryo can be created.

The process for creating a three parent embryo. Source: Human Fertilisation and Embryology Authority
Don’t forget that you probably won’t do this to just one embryo because you want to increase the chance of success. Just as in the regular IVF process, multiple three parent embryos will likely be created, and several of them will either be tossed due to genetic deficiencies that crop up after step 3 or kept in limbo through cryopreservation.
In the discussions I’ve seen so far, no one has decried the killing of the donor’s embryo, which is a human life being sacrificed for the idol of having a healthy baby. All the supporters merely point out that either: a) I should be able to have a baby (or a healthy baby) if I want to; or b) why don’t you want to help these poor men and women who can’t have a baby (or a healthy baby). The fact that you have to purposely end a human life in order to have that healthy baby is what’s fundamentally wrong with this procedure. One life is deemed unworthy of life and it is being ended and discarded simply so that another, more “fitting,” life may continue.
Desiring healthy children is not, in and of itself, a false idol. But when we start doing whatever it takes to ensure that we have healthy children, including ending other human life, then it has become an idol.
What does that say about us as a society?
Updated: February 10, 2015 at 11:48 a.m. EST