Recently, the first known successful instance of a three-parent in vitro fertilization IVF embryo was created and a child was recently born. While the US and a number of other countries have temporarily banned such procedures while ethicists and lawmakers consider the implications (and following a failure of a similar technique in the 1990s), Mexico (where the current procedure occurred) has no such rules. Unlike gene editing which can have unknown consequences that need to be explored and carefully considered as we move forward with the technology, this procedure has few risks. There are clearly some cultural or religious objections, however, as there were in the early days of IVF.
Mitochondrial DNA is present in women’s eggs but not in spermatozoa. Mitrochodrial DNA is passed on from the mother to the child, and does not relate otherwise to one’s genome, per se. In other words, your genome is not your mitochondrial genome, and most of your traits are not linked to it or otherwise depend upon it. However, the mitochondria are known as the “powerhouse” of the cell, and there are diseases and infirmities that may derive from mitochondrial DNA problems, and that can be passed on to children. A process of in vitro fertilization that uses a donor for mitochondria separate from the donor of egg and sperm would be therapeutically useful to prevent the inheritance of inheritable diseases related to mitochondrial functioning.
Unlike germline-cell genome editing, which would attempt to correct errors in mitochondrial DNA by editing them out, IVF with mitochondrial donor would enable the protection of the embryo from m-DNA diseases or infirmities without delving into the tricky area of genetic engineering. Any healthy donor of mDNA will suffice to help avoid illness in the offspring, and the process of IVF is well known and generally accepted as a means of helping couples who wish to have children and have had trouble through traditional means. In the recent case cited above, the technique allowed a woman with a rare genetic disorder of her mitochondrial DNA to have a child without the risk of passing on that trait.
There may be some cultural or social hostility to the notion of 3-person donor IVF from the standpoint of its potential to challenge traditional notions of parenthood. That every child has, until recently, has only two biological parents will suddenly no longer be the hard and fast rule. Now it is possible for a child to have, in some biological sense, three parents: the producer of the egg, the producer of the sperm, and the donor of the mitochondria. In most therapeutic cases, where a mitochondrial donor has given their m-DNA to help to address some disease and to help ensure the health of the offspring, assuming informed consent and binding agreements, the mitochondrial donor will assume no rights to the offspring parentally or otherwise, just as with donors of eggs or sperm under some circumstances contractually relinquish their rights under fully informed consent to the offspring.
Issues will remain for us yet to debate and discover for the use of 3-donor IVF in the future, though, if it is used “cosmetically” to accommodate new and evolving notions of families, such as those involving polyamory. Laws and social mores continue to regulate the nature of some families even as societies become more liberal in their views of what constitutes a marriage and family. Whether 3-donor IVF becomes a means for more complex familial relationships ought to be considered as we move forward with the technology, even as we recognize its obvious therapeutic value in helping people to conceive healthy children. The US and other nations should drop their ban on this medically important advance.
Questions about the nature of families, rights, and responsibilities for “cosmetic” 3-donor IVF are inherently political, necessitating new legal recognitions, just as recent liberalizing of marriage laws has involved political change. Therapeutic IVF, whether involving 3 or two donors, remains well constrained by existing legal frameworks and agreements that establish the rights and responsibilities of donors before any procedure is undertaken, coupled with adequate information and consent. But now is a good time to consider the possibilities presented by the technology for challenging and altering our notions of traditional family arrangements and parental roles.