Survival of the beautiful: Reproductive fitness and sexual selection in the age of egg and sperm donation for assisted reproduction
Carol Lynn Curchoe, Ph.D.
San Diego Fertility Center
Choosing a tissue source from an egg donor or sperm donor website or catalogue is a unique experience, distinctly different from viewing a dating website, pornography, or erotic material. LGBTQ intended parents choose a reproductive partner separately from the gender they are primarily attracted to, and the partners they engage in same-sex behavior (SSB) with. The LGBTQ set of preferences for reproductive purposes is an underreported and understudied phenomenon. Due to recent advances and availability in reproductive technology and increased legal recognition, we now have the opportunity to better understand these preferences and in turn, design better user experiences that cater to them. Thematically, LGBTQ parenthood journeys have been undertreated in contemporary art. The journey to LGBTQ parenthood is emerging as an experience formative to contemporary human culture, deserving of further treatment in both the natural sciences and arts and humanities.
A long-overdue phenomenon of our current historical and political moment sees same-sex relationships increasingly receiving the same legal recognition as straight marriages. Concomitantly, advances in assisted reproductive technologies (ART), such as egg and sperm donation, and surrogacy coupled with IVF, are increasing the “reproductive fitness” of individuals who previously may not have reproduced.
Reproductive fitness can refer to genes or their expression in a specific environment. The term describes individual reproductive success.
Straight people are in the majority, but gay men, lesbians, bisexuals, and transgender people account for a significant minority – a recent survey found 7 percent of women and 8 percent of men in the U.S. identify as L, G, B, or T. This is referred to as a “paradox” in evolutionary terms. Same-sex attraction should result in reduced reproductive fitness; however, it persists readily in human populations despite its apparent selective disadvantages.
Worldwide, new standards have been proposed for the definition of “infertility” suggesting that the inability to find a suitable sexual partner – or the lack of sexual relationships that could result in conception – could be considered a disability. This standard is inclusive of the rights of all individuals to have a family, and that includes single men, single women, gay men, and gay women.
Since 1996, the U.S. Centers for Disease Control and Prevention has published annual reports detailing the success rates of various ART procedures, under the mandate of the Fertility Clinic Success Rate and Certification Act of 1992. 42 U.S.C.§ 201 (1992). They report that the number of attempted conception cycles using donor eggs has risen from 1,802 in 1992 to 17,4962 in 2013, with 47% of transfers resulting in live births.
Of egg donor recipient cycles, we do not know how many are intended to treat straight-female infertility, versus other types of infertility (for example having an “absent female partner” i.e. a homosexual male: male couple or single man).
The U.S. is one of the only locations for legal and seamless tissue donation and compensated surrogacy that is also legal for LGBTQ intended parents to pursue. Many countries have restrictions on who can complete the surrogacy process, as well as limits on compensation, if surrogacy and tissue donation are legal in the first place. Countries such as France, Germany, Italy, Spain, Portugal and Bulgaria prohibit all forms of surrogacy. In countries like the UK, Ireland, Denmark and Belgium, surrogacy is allowed where the surrogate mother is not paid, or only paid for reasonable expenses.
Within the United States, surrogacy laws vary by state, and only half of fertility clinics that belong to the Society for Assisted Reproductive Technology (SART) include any LGBT content at all on their websites. Clinics in the Midwest and South were significantly less likely to have any LGTBQ content, whereas, larger clinics in Northeastern and Western regions, located in states with mandated insurance coverage for reproductive services contained LGBTQ information on their websites (1).
Taken together, these socio-political and infertility treatment advances mean that LGBTQ individuals are likely currently having biological children at substantially higher rates today than in the near past, and will likely continue to see increasing rates in the future, as further advances in social justice are achieved.
ART: Uncoupling Reproductive Fitness from Mate Selection
Much like a dating website, egg donor websites display photos, medical histories, eye color, height, ethnicity or race, education level, personal interests, and family histories.
Egg donor choice has been studied in infertile women. Between 2008 and 2012, the percentage of infertile women who said they wanted an egg donor from a "similar gene pool" declined from 40 percent to 25 percent. At the same time, looking for a baby with a "similar appearance" was relatively rare, with 15 percent of women in 2008 saying it was important to them, and 22 percent saying so in 2012. From 2008 to 2012, the percent of women who cared about a donor's "intelligence" increased from 18 percent to 55 percent, and the percent that cared about "athletic ability" increased from 1 percent to 17 percent (2).
Due to increasing availability (and legality) of tissue donation and surrogacy, LGBTQ individuals can now choose reproductive partners separately from the partners they engage in SSB with, and we have the opportunity to understand what the LGBTQ set of preferences for reproductive purposes are. These phenomena have been extensively studied in heterosexual individuals (3-4), and the heterosexual set of standards for “physical attractiveness” informs the idealized images used in advertising (5).
Researchers have characterized the sexual attraction of gay men as being sexually attracted to men in their late teens and early twenties, prioritizing physical attractiveness over status (6-7). There is very little (to no) published evidence examining gay intended parents behaviors and choices with respect to either tissue donation or surrogacy. One abstract (from a conference proceedings (8) characterizes the attitudes of very small number of gay male intended parents with respect to the number of embryos transferred into their gestational carrier during a gestational surrogacy/egg donation IVF cycle.
The dearth of publications demonstrates that we do not yet have good theoretical, comparative, or experimental predictive approaches to ask these types of questions.
An Apparent Reproductive Fitness Paradox.
SSB is thought to impose a direct fitness cost on individuals that express it, and therefore surely must represent an ‘evolutionary paradox’ that is begging for an explanation. But does it really represent a paradox? Or are we shoehorning the study of SSB with the biased idea that it should be a “paradox?”
“In order to avoid an actual description of the mysterious arbitrariness of nature, we have to ignore almost everything interesting.” ~Richard Prum, Professor of ecology at Yale University and curator of birds at the Peabody Museum.
Ample evidence exists that there is a heritable genetic component of SSB, a gay man is more likely than a straight man to have a gay biological brother, and lesbians are more likely to have gay sisters (9-11). However, despite years of robust study, there is limited evidence for genetic mechanisms governing SSB inheritance (12-14). One hypothesis suggests that LGBTQ folks might make up for a lack of biological children by boosting the reproductive success of their close relatives. There is evidence that X-linked genes associated with SSB in men provides a fitness boost in women (sexual antagonism). Women related to gay men have significantly more children (15), thereby compensating for the reduced fecundity of homosexuals. In a competing theory called “overdominance” it has been proposed that a double genetic dose (homozygous) may result in SSB, but that a half dose (heterozygous) may confer a balancing fitness advantage (16).
Sexual selection, the concept that females choose mates based on traits that they arbitrarily consider beautiful, could also play an un-recognized role in the mechanisms of SSB inheritance. The role that sexual selection plays in the descent of man has been established previously (17). What if the male relatives of gay men are simply irresistible to women, increasing the fitness of a gay individual’s close male relatives? Could female preference, instead of the standard male:male competition model, be driving the evolution of SSB? Could it be that broadening the view of mate selection to include a model where families, or even societies as a whole are chosen by women, due to the fitness signals that having a gay relative (or living in a society that has gay members) gives? Those signals could indicate familial or social stability – this society or this family structure can amply support individuals who have essentially no reproductive fitness.
In one recent example, we have seen the entrenched “male competition” bias neatly turned around by female choice (18). The concept that sperm race to the egg, that the “first to the finish line” achieves fertilization, is being replaced by evidence of the egg as an equal and active player in fertilization.
The hypotheses presented above are not mutually exclusive to the theory of X-linked sexual antagonism, and predictions about the inheritance and fitness effects of alleles can be tested in same-sex couples that are undergoing ART to directly test these hypotheses, and more. Once recent study predicts that nearly 400 million people in 2100 may be alive as a result of ART. The figure, accounts for three percent of the world's projected population, and includes not only those conceived using ART, but also their descendants (19).
As an artifact of previous socio-political and cultural times, many of the foundational studies mentioned above can be critiqued for sample size (for example, just 61 pairs of twins were sampled in the study that is most often cited as evidence of a genetic component of homosexuality), and the methodology and reproducibility (20).
ART births represent a significant and specific population to repeat these foundational studies, gather additional genetic evidence, and develop and test new models of inheritance in.
Impact of Obstetric and Infertility Practices on Allelic Directional Selection
We know that when alleles gain even a weak directional selection they can rapidly spread through a population. For example, genes for increasing fetal head circumference would have been strongly selected against before the advent of Caesarean sections, as mother and child both would have died in labor.
Although the instance of C-sections births varies widely, and as with all human studies there are various confounding factors, we see some evidence for a 10 to 20 per cent increase in the rate of “fetopelvic disproportion” (21) since the regular use of Caesarean sections. Researchers estimate cases where the baby cannot fit through the birth canal have increased from 30 in 1,000 in the 1960s to 36 in 1,000 births today.
Certainly, if gene evolution can be pressured by obstetric practices, it can also be influenced by use of ART. By definition, ART involves a combination of artificial environments and selection criteria that are distinctively different from those of natural reproduction.
In theory, use of ART could potentially produce larger evolutionary effects more quickly, as it directly influences reproductive success. ART has previously been shown to influence human evolution for heritable traits in subfertile couples (22), as well as a host of phenotypic epigenetically controlled traits, for example, intrauterine growth rate, placental gene expression, birthweight of newborns and body weight at 2 years of age, and many more (23).
Same-sex sexual behavior also directly influences reproductive success, and is therefore, a candidate to be studied for strong evolutionary selection within the context of egg and sperm donation for LGBTQ reproduction.
In the natural sciences, it can sometimes be difficult to perform research of this kind. Heteronormative bias, language, and assumptions can creep into even the best-designed studies. In many countries homosexuality is criminally prosecuted, biasing the population of study participants to favor Western, white, wealthier individuals. The research itself can be socio-politically exploited, as fertility- who can have babies, and when, and how- is organized into systems of power that reward some people and suppress others. Infertility seems to be a ripe topic for artistic expression engaged in the politics of sexuality and human rights- yet, expressions of LGBTQ parentage are rare.
A Missing Art- Where are LBTQ Expressions of In/fertility?
Mesolithic Goddess figurines, Venus/ Aphrodite, Demeter, and numerous contemporary examples make it clear that fertility has been explored and celebrated in art throughout the ages. Infertility (and the prevention of pregnancy) on the other hand is taboo, and the consequences of which can include depression, anxiety, ostracism, physical abuse, and even suicide.
The standard view of queer art tends to focus on the depiction of homoeroticism, queer bodies, queer sex, of themes dealing with AIDS or post-identity politics. Erotic homosexuality is thought to be represented as far back in human history as Mesolithic art and petroglyphs through to present day (24). However, artistic expressions of the journey to achieve LGBTQ parenthood are very difficult to come by.
The European Society of Human Reproduction and Embryology (ESHRE) is holding the world’s first arts festival dedicated to fertility, infertility, modern families and the science of making babies. The website for the “Art at ESHRE” exhibit reveals that all of the featured artists are heteronormative presenting cis-couples.
LGBTQ intended parents also experience failed IVF cycles, the heartbreak and roller coaster of frozen embryo transfer, the grief and devastation of miscarriage or fetal demise (through use of ART, gay men are now experiencing miscarriage and fetal loss in new and unique ways,) and the joys and frustrations of long sought and hard-won parenthood. They struggle with the concept of having the “perfect family.” They experience issues of parental legitimacy, body dysmorphia and general distrust of the medical establishment for marginalizing and neglecting their bodies.
For example, transwomen, and masculine presenting women may want to have their own genetic children, and elect to undergo hormonal stimulation and oocyte-retrievals. They need particular care to feel comfortable when being stimulated with high levels of reproductive hormones, and during the multiple ultrasounds and procedures on organs and body parts that might not match the gender they are presenting as, and that they might not even be comfortable with having still.
Consider another example: there are thousands of examples of artistic expressions of women nursing and breastfeeding (a Breastfeeding Art Instagram account, for example has thousands upon thousands of followers and images). Inclusive intersectional representation is now warranted. Transwomen have recently been induced to lactate (25) for the first (documented) time. Induced two parent co-nursing in queer families, and supplemental nursing systems (SNS) involving a bottle or syringe attached to a tube placed at the nipple of parents who are unable to lactate are all strategies to help parents achieve their own personal nursing goals.
How could an infertility art festival, such as the one at ESHRE, purport to feature “modern families” but yet not include any LGBTQ expressions of parenting?
It is challenging to find any artistic expression (beside photography of individuals) that explores, celebrates, and illuminates LGBTQ parenting- never mind artistic expression that helps us to understand reproductive partner preference in LGTBQ populations.
Lee Paje uses tondos to defy stereotypes by naturalizing queer narratives, in this case by offering a simple portrait of an unconventional family. In 2016, in the U.K. a beautiful commemorative stamp by artist and United Nations postal administration (UNPA) art director Sergio Baradat, promoted equal rights for LGTQ parents.
Each in their own right- homosexuality, queerness, and infertility are all or have all been taboo topics. The journey to LGBTQ parenthood is emerging as an experience formative to human nature, and artistic expression is needed to celebrate the joy of new life and parenthood, even in the face of overwhelming odds.
Egg and sperm donor “catalogues” are a one size fits–all model where user experiences are not typically stratified to target LGBTQ reproductive preferences, because they are an essentially unknown and understudied aspect of human reproduction. LGBTQ specific content is not included on half of all fertility clinic websites of SART member clinics. In general, because this is an emerging field of treatment, LGBTQ specific content is not only underrepresented on fertility clinics websites but also in the scientific literature, and in artistic representation of all kinds. Additionally, the examination of sexual selection and reproductive partner choice in the context of reproductive tissue donation could be expanded in the natural sciences to examine their role as factors influencing evolutionary change in LGBTQ populations, and in the arts and humanities to illuminate and examine aspects of the inner life of LGBTQ individuals, the history of our culture, and the politics and mores during this socio-political moment. ART may be influencing human evolution in a population that is enjoying increased reproductive fitness during this current historical and political moment and thematically, LGBTQ parenthood journeys have been undertreated in contemporary art- leaving open a wide playing field to treat these topics. Finally, further study of the set of LGBTQ preferences for reproductive purposes is warranted to design user-specific digital art assets for egg and sperm donor catalogues and fertility clinic websites.
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