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Human In Vitro Gametogenesis and the Same-Sex Marriage Debate

Written by César Palacios-González

It seems that in the not-so-distant future, scientists will be able to create functional human gametes (i.e. eggs and sperm) in a laboratory setting. In other words, they will be able to create human gametes outside of the human body. And just as there is in vitro fertilization (IVF), there will be in vitro gametogenesis (IVG). This means that our already long list of human reproductive acronyms –IVF, PGD, ICSI, PNT, PBT1, PBT2, MST, UTx, CT, etc.–  will get a bit longer. At present, some of the best biology labs from around the world are actively working on how to achieve such goal, and non-human animal models have shown some amazing results.

For starters, scientists have successfully derived in a laboratory setting mouse oocyte-like cells and sperm-like cells from induced pluripotent stem cells and embryonic stem cells. And, most surprisingly, they have been able to create what has been called “cross-sex gametes”. This means that they have been able to create sperm-like cells from female mice, and oocyte-like cells from male mice (I use the terms ‘sperm-like’ and ‘oocyte-like’ because these cells are not identical to naturally occurring gametes). Some of such cross-sex gametes have, in turn, been capable of producing live offspring.

This research is also being applied to humans. Scientists are investigating how to produce human oocytes and sperm, and human cross-sex gametes. In the most general terms we can say that human IVG research has two objectives: (1) to understand gamete formation and maturation, and (2) to generate gametes that could be used for reproductive purposes. IVG, if successful, would allow some congenitally gamete-related infertile men and women, and men and women that suffer from gamete-related infertility due to disease or trauma, to have genetically related children. For example, a congenitally azoospermic individual or someone who lost his penis and testicles due to a bike accident would both still have the opportunity to have genetically related children. Likewise, if cross-sex gametes are successfully developed, IVG would allow same-sex couples to have genetically related children. In the case of males, they would still need at this point the aid of a surrogate.

So far bioethicists have explored two different sets of issues regarding IVG. On the one hand, they have explored the new possibilities that IVG would open in terms of human reproduction: solo reproduction, multiplex parenting, same-sex reproduction, in vitro eugenics. On the other hand, they have explored possible ethical objections to IVG: that it would be unnatural, too risky,  or a waste of resources, etc. The state of the bioethical debate in regards to IVG is such that when it finally arrives no informed person will be able to say that the ethics needs to catch up with the science. Now, even when the two former areas of inquiry are really interesting, I want to briefly explore in what follows a different issue: how the successful development of cross-sex gametes would affect the same-sex marriage debate.

Let me begin by making two clarifications. First, I acknowledge that starting from ‘let us suppose that this technology will work very well’ means starting from a very big ‘if’, but let this be so. Second, the philosophical literature on the same-sex marriage debate is vast (see, for example, here, here, and here) and the point that I will make is limited to one particular case against same-sex marriage, that which ties marriage to reproduction.

The successful development, and use, of cross-sex gametes would have devastating consequences for those who defend what can be called the Procreative Account of Marriage (PAM). According to PAM, as presented by Maggie Gallagher:

“Marriage is intrinsically a sexual union of husband and wife, because these are the only unions that can make new life and connect those children in love to their co-creators, their mother and father”.


“The critical public or ‘civil’ task of marriage is to regulate sexual relationships between men and women in order to reduce the likelihood that children (and their mothers, and society) will face the burdens of fatherlessness, and increase the likelihood that there will be a next generation that will be raised by their mothers and fathers in one family, where both parents are committed to each other and to their children”.

The first thing to say here is that while most children are created via sexual relationships, this is now only one of many avenues to create children. At present time, children can be created in scenarios that do not involve sexual intercourse. For example, men in prison could send their semen to their partners, and they in turn could use it for creating a child. The same could be the case for soldiers that are deployed far away from their partners. Being this the case, we can either ditch the sexual union component of the previous account of marriage, or accept that the unions of heterosexual couples who do not have sex and who have children (without sexual intercourse) are not marriages. The second option should be rejected by advocates of PAM, since they accept that the unions of asexual heterosexual childless couples are marriages.

Secondly, with the advent of cross-sex gametes, same-sex couples will be able to make new life ‘by themselves’ (lesbian couples can already do this via a different reproductive technology, but they still need a sperm donor). This, obviously, will entail that it will no longer be the case that only heterosexual unions can make new life. At such point, advocates of PAM will have no other option but to accept that marriage is the union of husband and husband, or wife and wife, or wife and husband, because all of these configurations “can make new life and connect those children in love to their co-creators”. The arrival of cross-sex gametes will make it the case that the definition of marriage endorsed by advocates of PAM will also inherently include same-sex couples.

Let me finish by pointing out two things. First, the above case does not detract from arguments that have already been presented in favour of same-sex marriage (see the links, above, on the philosophical literature on same-sex marriage). It will, in due course, just strengthen the case for same-sex marriage. Second, it is true that what I have presented here is an argument for the future, in that cross-sex gametes are not a reality yet. But even when this is so, this does not detract from its soundness, empirical facts permitting.





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1 Comment on this post

  1. Dr. Elizabeth A. Leonard

    This is wonderful news for my daughter, who was diagnosed with Primary Ovarian Failure, at the age of 14. Human egg freezing was not perfected at that time (2002) and her only pregnancy option was IVF with a donor egg. This raises a whole new level of options and of course, hope. Thank you so much!

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