The Future of In-Vitro Fertilization: 3-Donor IVF
The latest hot topic in science news is at the center of some controversy, and spotlights current innovations in fertility treatments: Three donor In-Vitro Fertilization (IVF). Many news outlets are eager to share personal opinions on this life-changing procedure, and some even scrutinize it to a demeanor of a “wacky sci-fi plot”. However, such demeaning connotations to breakthrough research that creates opportunities for healthy future families should not be abashed so hastily. As Albert Einstein once said, “If at first the idea is not absurd, then there is no hope for it”.
It is important to keep in mind that this type of fertility treatment option is geared toward a specific population: women who have mitochondrial diseases. These types of diseases affect about 1 in every 5,000-10,000 individuals. Three donor IVF offers the opportunity to hopeful-mothers with mitochondrial diseases the ability to have a child who is still biologically theirs, without the risk of passing on a debilitating illness that can cause ailments such as muscle weakness, blindness, and even heart failure. By using two separate female egg donors, we are able to use one egg with healthy mitochondria from a donor to, in essence, replace the unhealthy mitochondria of the diseased mother’s egg.
In order to make more well rounded judgments about this procedure, we must better comprehend the science behind it. There are two chief techniques being studied for conductance of 3 donor IVF’s. One method utilizes taking a fertilized egg of the mother (woman with the mitochondrial disease), and then removing the nucleus. We then insert that nucleus into the cytoplasm of another donor egg that has also had its nucleus removed. In effect, we are just switching the two egg nuclei. This donor egg that the mother’s nucleolus has been placed in, contains healthy mitochondria, and thus prevents contraction of mitochondrial disease to the child. The second technique is fundamentally identical to the first, the only difference is the egg isn’t fertilized until after the transplant of the nucleus. The primary difference in the two techniques, then, is when the egg is fertilized with the father’s sperm, either before or after the nucleus exchange of the two eggs.
The nucleus is principally the container that all of the mother’s genetic material is stored in. It contains the chromosomes from the mother, which are carries of our genetic makeup, or DNA, which make us who we are. The cytoplasm is the area that houses the whole cell including the organelles which maintain its function. One specific type of organelle is the mitochondria. The mitochondria are the primary energy producers for the cell. These are extremely small and fragile structures that take immense precision to extract, making this procedure so novel and challenging.
So, what is all the controversy about if the child still receives all of their genetic information from the mother in her egg’s nucleus? Well, mitochondria are very unique because they contain their own personal DNA. Due to mitochondria possessing their own DNA, this means that the child of the three donor IVF will in fact posses DNA from three separate people, hence the common name “three parent IVF”. However, this third contribution of genes from mitochondria is minimal. The fertilization of the egg’s nucleus with the sperm’s nucleus of the father, combine and mix DNA in a 50/50 proportion creating children that reflect their mother and father equally. This will not change with the three donor IVF, with the exception that the mitochondria in every cell are different. All other inheritable characteristics of the child will still be from the father and mother. Mitochondria’s DNA, as far as we know, doesn’t seem to affect any other expression of traits other than the ability to produce energy in a cell. Therefore, the mitochondrial DNA inherited from a third parent will be a fraction of a percent of the child’s overall genetic makeup. Fundamentally, the child will still be biologically identical to its parents, with the exception of having healthy mitochondria in its cells from a third parent, instead of the unhealthy ones he or she would have received from their mother.
On February 3, 2015, the United Kingdom House of Commons voted to approve regulations of the creation of children with DNA from three people in order to prevent transmission of disease. The case also received approval from the House of Lords on February 24, which fully passed the law allowing three donor IVF to be a legal procedure in the UK effective in October 2015. This procedure is still not permitted in the United States, but the US Food and Drug Administration is currently being requested to consider the legalization of the procedure by the Institute of Medicine in a series of meetings over the next four months.
Overall, three donor IVF gives women with rare and tragic mitochondrial diseases the ability to have children without the risk of passing on their malady. What may seem like a farfetched fantasy is slowly becoming a reality for these diseased women with motherly aspirations. Many may morally oppose these novel procedures, and it is important to understand and respect these opinions. It is also equally important to understand and respect the opinion of those whom may benefit from such a procedure in bringing the miracle of a healthy child to their family. There may never be complete agreement on such issues, but it is important to understand both vantage points. After all, not long ago many people were unsettled with the idea of general two donor IVF, yet it has brought the miracle of life to over 60,000 couples in 2012 alone. As the UK Prime Minister David Cameron put it, "We're not playing god here, we're just making sure that two parents who want a healthy baby can have one".
