Tag Archives: Netherlands

Sensate Vagina Pedicled-Spot for Male-to-Female Transsexuals: The Experience in the First 50 Patients – Review

A Dutch surgeon has developed a new technique to create erotic sensations in trans women’s vaginas.

The author operated on 50 trans women (born male) between August 2009 and May 2014. He created a a sensate vagina pedicled-spot and a neo-clitoris during primary penile skin inversion vaginoplasty. Part of the corona glandis of the penis is “pedicled on the dorsal penile neurovascular bundles” and put into the neo-vagina.

The goal of the operation is to increase sexual sensitivity for trans women.

“One of the goals of sex reassignment surgery is to create tactile and erogenous sensitivity in the reconstructed genitals. A neo-clitoroplasty performed during primary gender-confirming surgery for male-to-female transsexuals, is a procedure which has been considered state of the art for over 40 years, gives sexual functionality to the neo-female genitalia. This goal falls short due to the inner neo-vagina’s lack of erogenous sensitivity, having instead only tactile sensitivity of the skin and prostate. This shortcoming persists despite the refinements to the vaginoplasty throughout the years.

To improve the sexual functionality, I have innovated a technique that creates a sexual sensate vagina pedicled-spot in the male-to-female transsexuals, which could be compared with the G-spot, in combination with neo-clitoroplasty.”

At 15 weeks, 82% of the patients had sexual feelings in the clitoris and 62% had sexual feelings in the sensate pedicled spot within the vagina. However, the study also says that erogeneous sensibility recurred in all the patients; so perhaps some patients developed sensitivity after 15 weeks.

The study does not discuss orgasms or patient satisfaction. There is no information on whether or not the trans women were having active sex lives. Future studies should look at these issues.

Future research should also look at whether there are any differences between neo-clitorises created with this procedure and other neo-clitorises. Does it affect the clitoris if part of the corona glandis is used to create the sensate pedicled spot within the vagina?

This is an exciting first study, however. Creating sexual arousal and pleasure is an important part of gender reassignment surgery.

What about safety?

The technique added 15 minutes to the time of the operation. This might increase the risk of blood clots, although they did not report any.

Complications included:

6% per-operative rectal lesions which were directly closed

2% post-operative bleeding

34% one or more aesthetic corrections involving the introitus, labia majora, or clitoral region,

4% infections treated with antibiotics

10% post-operative bladder retention which resolved spontaneously after 1 week

20% had meatoplasty to enlarge the opening for peeing

It is difficult to evaluate the relative rate of complications. The rate of bleeding in this series compares well to rates reported in this 2010 German study (6%) and this 2011 overview from the United Kingdom (10%). On the other hand, their rate for problems with narrowing of the urethra is much higher than in the other two studies (none and 3-4% respectively). In this review of studies, a 2001 German study had higher rates of complications. None of the other studies discuss aesthetic corrections.

We need studies that compare the relative safety and rates of complications of different surgical procedures, including this one.

More Details on the Study:

40% of the patients felt sensations in the clitoris an average of 11 weeks before the sensate pedicled spot, 40% felt sensations in both at the same time, 4% felt sensations in the sensate pedicled spot first, and 12% were unclear on the timing.

Erogenous feelings in the clitoris recurred after 7.6 weeks on average in 46 patients, with a range of 5 days to 48 weeks. Erogenous feelings in the sensate pedicled spot recurred after 12.6 weeks on average in 44 patients, again with a range of 5 days to 48 weeks.

For one patient, “the sensate pedicled-spot was lost due to pressure but remarkably the sensate potency was not lost in this case.”

“Hypersensibility occurred in two patients of the sensate pedicled-spot along with hypersensibility of the clitoris.”

The average age of the patients was 38.4 years (range 19–65 years).

Follow-up ranged from 17 to 73 months (mean 46.7 months) and is still ongoing.

You can read details of the surgical technique used below.

Original source (contains graphic photos of surgery):

Sensate Vagina Pedicled-Spot for Male-to-Female Transsexuals: The Experience in the First 50 Patients by Kanhai RC in Aesthetic Plast Surg. 2016 Apr;40(2):284-7.

Technique described in this study:

“For the vaginoplasty, I employ a modification of the abdominally pedicled penile skin inversion technique enhanced by a dorsal rectangular scrotal skin flap. For this, the penile skin tube with the fascia penis superficialis (dartos fascia) and superficial dorsal cutaneous veins adherent to it are dissected from the erectile corpora, leaving the dorsal neurovascular bundles unharmed and covered by Buck’s deep penile fascia. Subsequently, two longitudinal incisions through Buck’s fascia, but not through the tunica albuginea, are made bilateral to the dorsal neurovascular bundles. By blunt and sharp dissection, the intermediate fascia, including both dorsal neurovascular bundles, is raised from the tunica albuginea all the way from the base of the glans to the urogenital diaphragm. After undermining part of the glans, two small parts of its corona and a part of the preputium is left attached to this pedicle which will be divided. One part will serve as a vascularized sensate neoclitoris with its preputial hood and the other part will be the sensate pedicled-spot. The sensate pedicled-spot will be attached to the anterior wall of the vagina in the ostium region and invisible in frontal view.”

Evidence for an Altered Sex Ratio in Clinic-Referred Adolescents with Gender Dysphoria – Review

This is a highly significant study showing that the population of teenagers referred for gender dysphoria is changing. It is noteworthy that this is happening in two different countries.

The sex ratio is changing:

The sex ratio of teenagers seeking help for gender dysphoria has changed at two clinics, one in Canada and one in the Netherlands.

Before 2006, more male than female teenagers sought transition at these clinics. Since 2006, they have seen more female teenagers than male teenagers.

Sex ratio for teenage patients at the Canadian Gender Identity Service:

  • 1999-2005 – 68% male, 32% female
  • 2006-2013 – 36% male, 64% female

Sex ratio for teenage patients at the Dutch Center for Expertise on Gender Dysphoria:

  • 1989-2005 – 59% male, 41% female
  • 2006-2013 – 37% male, 63% female

At the Canadian clinic, there was no change in the sex ratio of teenagers referred for psychiatric issues.* In both time periods, roughly two-thirds of their other patients were male.

According to the authors, “In adult samples [of transitioners], in almost all cases, the number of natal males either exceeds the number of natal females or the sex ratio is near parity.” Poland and Japan are exceptions; in those countries more females transition than males.

In addition, clinics for children with gender dysphoria have found that the number of males exceeds the number of females.

More teenagers are transitioning:

The number of teens of both sexes has increased over time, although the increase is larger for the female teenagers.

Increases at the Canadian clinic:

Female teenagers

  • 46 in 30 years (1976-2005)
  • 129 in 8 years (2006-2013)

Male teenagers

  • 80 in 30 years (1976-2005)
  • 73 in 8 years (2006-2013)

Increases at the Dutch clinic:

Female teenagers

  • 77 in 17 years (1989-2005)
  • 148 in 8 years (2006-2013)

Male teenagers

  • 109 in 17 years (1989-2005)
  • 86 in 8 years (2006-2013)

In other words, the Canadian clinic saw nearly nearly three times as many female teens in the past 8 years as they had seen in the previous thirty. The Dutch clinic saw nearly twice as many female teens in the past 8 years as they had seen in the previous seventeen.

Furthermore, “For many years in the Toronto clinic, the number of adolescent referrals was quite low. Between 1976 and 2003, for example, no more than five adolescents of one biological sex were assessed in a calendar year and, during this period, the number of males exceeded the number of females. Beginning in 2004, however, the number of adolescent referrals began to rise quite dramatically, which appears to be consistent with the observations of clinicians and researchers from other gender identity clinics.”

For earlier data on the increase in Canada, see this article.

Sexual orientation percentages have changed:

The Canadian clinic also looked at sexual orientation.

Sexual orientation of females:

  • 1976-2005 – 89% primarily attracted to females; 11% other
  • 2006-2013 – 64% primarily attracted to females; 36% other

Other could mean primarily attracted to males, bisexual, or asexual.

Sexual orientation of males:

  • 1976-2005 – 67% primarily attracted to males, 33% other
  • 2006-2013 – 44% primarily attracted to males, 56% other

Other could mean primarily attracted to females, bisexual, or asexual.

To put it another way, in the past most of the teenagers would have been gay if they weren’t transgender. If they transitioned, they would live their lives as straight people.

In 2006-2013 most of the male teenagers would have been straight, bisexual, or asexual if they weren’t transgender. If they transition, some of them will live their lives as lesbians.

One-third of the female teenagers in 2006-2013 would have been straight, bisexual, or asexual if they weren’t transgender. If they transition, some of them will live their lives as gay men.

What’s going on?

Why are we seeing more teenagers seeking help for gender dysphoria?

Why is the increase greater among female teens than males?

And why are we seeing a shift in the sexual orientation of these teens? Was it harder in the past to come out as transgender if you were seen as straight? Or is this a group of people who were less likely to have gender dysphoria in the past?

Has something changed in our environment that increases the number of people with gender dysphoria? What would affect more females than males? Why would it affect teenagers more than children (see this earlier article)? How would it fit with the changing percentages related to sexual orientation?

Is it just that there were always this many teenagers with gender dysphoria and now they are able to get care at an earlier age? How does that theory fit with the change in the sex ratio of teens applying to the clinic? with changes in their sexual orientation?

Clearly, we need more research to sort out these questions.

The authors speculate about possible explanations for the change in the sex ratio at their clinics.

They suggest that the general increase in patients might be due to a combination of destigmatization and more awareness of the biomedical treatments available to teens. However, they point out that this does not explain why more females would apply for treatment.

I don’t think we can know why the number of patients has increased without further research – research which is desperately needed.

The increase in the number of female patients at the Toronto clinic was not caused by a change in the severity of cases; they found that there was no significant relationship between severity of dysphoria and year assessed.

However, for male teens in Toronto, there was a weak correlation between severity of dysphoria and year assessed. “More recently assessed cases had moderately higher GD severity.” This only explained 6.7% of the variance. Therefore “it is unlikely that the recent inversion in the sex ratio can be accounted for by a substantive change in severity variation.”

On the other hand, they only have data on the severity of dysphoria starting in 2001 and the number of cases began increasing in 2004.

The change in the sex ratio was not due to females entering puberty at an earlier age; both clinics found no significant difference for the mean ages when females and males came to the clinic.

The sex ratio did not change due to the shift in sexual orientation. A logistical regression analysis did not find evidence for a sex x sexual orientation interaction.**

The authors suggest that perhaps the explanation for the change in the sex ratio is that it is harder for males to transition to a female role than for females to transition to a male one.

I find this unconvincing as this would have been true in the past when more male teenagers than females applied to their clinic. Nor would this hypothesis explain the shift in sexual orientation.

Here is their full explanation:

“Given that there is at least some overlap in the gender-variant developmental histories of early-onset individuals with GD and some gay men and lesbians, it might, therefore, be asked whether or not degree of stigmatization for gender-variant behavior might account for the recent inversion in the sex ratio of GD adolescents. It is well-known that cross-gender behavior in children is subject to more social stigma (e.g., peer rejection and peer teasing) in males than in females, in both clinic-referred adolescents with GD and in the general population[26–30]. Thus, it could be argued that it is easier for adolescent females to “come out” as transgendered than it is for adolescent males to come out as transgendered because masculine behavior is subject to less social sanction than feminine behavior. Some support for this was found in Shiffman’s [31] study of peer relations in adolescents with GD, in which adolescent males with GD reported more “social bullying” than adolescent females with GD. Given that a transgendered identity as an “identity option” has become much more visible over the past decade, it is conceivable, therefore, that such an identity option is easier for females to declare than it is for males because it does not elicit as much of a negative response. Thus, it could be argued that it is this sex difference in degree of stigmatization that accounts for the inversion in the sex ratio that we have identified in the two studies reported here. In other words, there are greater costs for a male to adopt a female gender identity in adolescence than it is for a female to adopt a male gender identity.”

A few more details about this study:

The first study looked at 328 teens (13-19) who were referred to the Toronto clinic between 1976 and 2013. The mean age at the time of referral was 16.66 years with no difference between the ages of males and females.

All of the teens met criteria for Gender Identity Disorder or Gender Identity Disorder Not Otherwise Specified. They were diagnosed using criteria in the relevant version of the DSM – this changed over time. The assessment of severity of dysphoria began in 2001.

The control group was 6,592 teens referred to their general clinic for psychiatric issues between 1999-2013. Eleven teens originally referred for psychiatric issues who were later referred to the Gender Identity Service were not included in this group.

The teens’ sexual orientation was determined by either clinical chart data or measurements on the Erotic Response and Orientation Scale and the Sexual History Questionnaire. This data was not available for five probands (aka people in this study).

The numbers for the sexual orientation of the teens at the Canadian clinic were:

1976-2005 (30 years)

  • 52 males primarily attracted to males
  • 26 males in the “other” category
  • 39 females primarily attracted to females
  • 5 in the “other” category

2006-2013 (8 years)

  • 32 males primarily attracted to males
  • 41 males in the “other” category
  • 82 females primarily attracted to females
  • 46 females in the “other” category

The clinic did not have data on the sexual orientation of five of the teenagers.

The second study looked at data on 420 teenagers (13 and up) referred to the Dutch clinic between 1989-2013.  Their mean age at the time of assessment was 16.14 and there was no significant age difference between males and females.

The second study did not include data on sexual orientation or a control group for comparison.

“The percentage of female adolescents from Amsterdam in the first time period did not differ significantly from the percentage of female adolescents from the Toronto clinic, and the percentage of female adolescents from Amsterdam in the second time period also did not differ from the percentage of female adolescents from the Toronto clinic, both χ2(1) < 1.”

This study is a follow-up to two earlier letters to the editor about changes in the teenage population at the clinic in Toronto: Is Gender Identity Disorder in Adolescents Coming out of the Closet? and Patterns of Referral to a Gender Identity Service for Children and Adolescents (1976–2011): Age, Sex Ratio, and Sexual Orientation.

The first letter discussed a rise in teenagers referred to the Canadian clinic between 2004-2007. The second letter discussed the continued increase in referrals from 2008-2011 and raises the question of a possible change in the sex ratio in 2008-2011.

Original Article:

Evidence for an Altered Sex Ratio in Clinic-Referred Adolescents with Gender Dysphoria by Aitken M1, Steensma TD, Blanchard R, VanderLaan DP, Wood H, Fuentes A, Spegg C, Wasserman L, Ames M, Fitzsimmons CL, Leef JH, Lishak V, Reim E, Takagi A, Vinik J, Wreford J, Cohen-Kettenis PT, de Vries AL, Kreukels BP, Zucker KJ in J Sex Med. 2015 Mar;12(3):756-63. doi: 10.1111/jsm.12817. Epub 2015 Jan 22.

* The Canadian clinic is the Gender Identity Service, within the Child, Youth, and Family Services (CYFS) at the Centre for Addiction and Mental Health in Toronto. The clinic in the Netherlands is the Center of Expertise on Gender Dysphoria at the VU University Medical Center in Amsterdam. This may explain why we have a comparison group for the Canadian patients with gender dysphoria, but not the Dutch ones.

**  “In the cohort examined in Study 1, perhaps it could be argued that, in the first time period, the greater number of biological males than biological females was an artifact of there being two prominent subtypes of GD (androphilic and nonandrophilic) in the former, whereas the latter were predominantly of only one subtype (gynephilic), but that this shifted in the second time period, with a greater number of females with a nongynephilic sexual orientation. However, the logistic regression analysis shown in Table 4 did not provide evidence for a sex × sexual orientation interaction. It only showed that a nonandrophilic or nongynephilic sexual orientation increased the odds that a proband presented in the second time period, but sexual orientation did not interact with probands’ biological sex.”

More Than Two Developmental Pathways in Children With Gender Dysphoria? – Review

There is a short but important piece about the persistence of gender dysphoria in children.

In this Dutch clinic, they found that:

70% of the children they diagnosed with gender dysphoria did not return to the clinic and transition; they “desisted” in their gender dysphoria.

95% of the children who desisted as teens did not return to the clinic as adults.

27% of the children they diagnosed with gender dysphoria transitioned as teenagers, 3% did so as adults.

Of the children who returned to the clinic before adulthood, 75% came back before they were 14 years old and 25% came back when they were between 14 and 18.

Boys were more likely to desist from their gender dysphoria than girls; 73% versus 61,5%. Conversely, more female children with gender dysphoria went on to transition; 38.5% versus 27%.

This is in line with earlier studies that have found that most children diagnosed with gender dysphoria change their minds when they are older, usually at puberty.

It also provides a follow-up to the question of whether or not the children who changed their minds still had gender dysphoria. They had access to a free medical transition, but did not return for it. It is possible that some of them may still return, but so far 95% have not.

This data also demonstrates what the authors call a third “developmental pathway” for children with gender dysphoria. This group seems to go through a “period of questioning sexual identity” as adolescents before deciding to transition as adults.

The clinic looked at the records of 150 adults who were diagnosed with gender dysphoria as children. The adults were now between 19 and 38 years old (average age = 25.9, SD 4.03). The sample was the first 150 consecutive patients the clinic had diagnosed who were now adults.

The authors discuss past studies of persistence of gender dysphoria in children. In the past, the persistence rate has been only 16% across studies, however, the diagnoses of gender dysphoria may have included some children who were simply gender non-conforming in their behavior. They suggest that in the future persistence rates may be higher as clinicians use a stricter definition of gender dysphoria.

In addition, they suggest that persistence rates might be higher if we include patients who choose to transition as adults. In this study, the persistence rate would only have been 27% if they did not include the 3% who transitioned as adults.

I would add that this data on persistence includes children who had access to puberty blockers and early transition. We need studies to determine if this affects rates of persistence and desistance.

We also need more studies of the children who did not return to the clinic and transition. Why didn’t they return? Did they completely lose their gender dysphoria? Are they happy? If they lost their gender dsyphoria, how did that happen? If they didn’t lose it, how are they dealing with it?

We have one study of children who desisted in their gender dysphoria, but we need more. (Desisting and persisting gender dysphoria after childhood.)

Finally, the authors provide an interesting discussion of the patients who did not transition as teenagers but returned to transition as adults:

“The average age of the 5 individuals who re-entered the clinic in adulthood was 24 years (range 21–37). Despite their knowledge of the availability of treatment for adolescents and the fact that treatment is covered by insurance, they did not apply for treatment during adolescence. Four (3 natal males and 1 natal female) tried to live as gay or lesbian persons for a long time, and 1 natal male had autism spectrum disorder. He reported that he needed to solve other problems in his life before he could address his GD. The others reported not having any problems with being homosexual. Yet, after having intimate and sexual experiences with same (natal) sex partners, they came to realize that living as a homosexual person did not solve their feelings of GD, and they felt increasingly drawn toward transitioning. All also mentioned that they were somewhat hesitant to start invasive treatments, such as hormone therapy and surgeries.”


“It would be worthwhile to know whether the GD of these “persisters-after-interruption” differs qualitatively or quantitatively from the GD of straight persisters and whether the groups differ in other respects. For instance, has the GD in the persisters-after-interruption group actually disappeared for some years or, as the reports of our young adults suggest, did they make a more or less conscious choice not to live according to their experienced gender? Knowing more about this developmental route would be clinically useful when counseling young people with GD.”

This data was presented in a letter to the editor.


More Than Two Developmental Pathways in Children With Gender Dysphoria? by Steensma TD, Cohen-Kettenis PT in J Am Acad Child Adolesc Psychiatry. 2015 Feb;54(2):147-8.

A review of “Gender Identity Disorder in Twins: A Review of the Case Report Literature”

The data on twins suggests that there is a genetic component to gender dysphoria.

It also suggests that other factors are involved in developing gender dysphoria.

Unfortunately, the data is weak because it is mostly made up of case studies.

In addition, the data on identical twins and the data on fraternal twins were collected in different ways.

It is possible that this review overestimates the influence of genes due to the way the data was collected.

I had thought that writing this review would be quick and easy; genes are involved, but they are not the only factor. The truth is that the data is flawed and we don’t have conclusive proof yet. What we do have is a suggestion that genes are involved in gender dysphoria and a need for more research in this area.

Data on twins with gender dysphoria is hard to collect because it is rare. This review is an important one and it shows that there are good reasons to keep looking for possible genetic links to gender dysphoria. It also shows that there are good reasons to look for non-genetic factors that play a role in developing gender dysphoria.

Now you have the summary of the results, back to the study. Why does it mattter if many of the reports on identical twins came from case studies?

Using case studies means that there is a possibility of selection bias.

People may be more likely to publish interesting cases. For example, the review includes one case study where both identical twins had gender dysphoria, but only one had schizophrenia. In another case study both identical twins had anorexia, but only one had gender dysphoria. These cases are interesting, but they may not be typical.

This can become a more serious problem if therapists are more likely to be interested in cases of twins who are both trans. Alternatively, there could be a selection bias in favor of writing about identical twins where only one twin is trans. Some therapists might unconsciously look for cases of twins that fit their own theory about the cause of gender dysphoria. (Read more about case studies and selection bias here.)

The results of this review suggest that there is a selection bias that favors identical twins over fraternal twins. In other words, people write up and publish cases of identical twins more often than fraternal twins.

This is not because trans people don’t have fraternal twins; the studies that reviewed clinic records found 19 sets of fraternal same-sex twins and only 7 sets of identical twins. Only 27% of the twins in this group were identical twins. This is not surprising; fraternal twins are more common than identical twins in the general public.

The other studies, in contrast, reported on 16 sets of identical twins and only 2 sets of fraternal twins. A whopping 89% of the twins in this group were identical twins.

The key to figuring out if gender dysphoria is genetic is to compare identical twins and fraternal twins. If identical twins are more likely to both have gender dysphoria than fraternal twins, you have a good case for a genetic contribution. So if the sets of identical twins are chosen in a different way from the sets of fraternal twins, you have a problem.

In fact, for this study most of the data on identical twins is coming from case reports; there might be a selection bias involved there. Almost all of the data on fraternal twins, however, is coming from comprehensive reviews of clinic records.

Reviews of case studies include a number of other problems.

You can’t be sure people are being diagnosed in the same way; you may not be looking at the same phenomenon. This review looked at people diagnosed by different therapists in at least ten different countries.* The dates of the studies ranged from 1956 to 2011. Some of the twins were children or teens, some were adults.

There may also be cultural or environmental differences that are relevant. For example, one of the case studies is of a pair of identical twins in Iran. Both twins are trans. We know that many people feel pressured to transition in Iran; what if that is a factor in this particular case? What if in another country, only one of the twins would have transitioned?

The era of the study might also affect gender dysphoria. For example, the Belgian clinic noticed that two of the fraternal twins with gender dysphoria they found had been born after in vitro fertilization. If IVF is a factor in gender dysphoria, it will only affect later cases.**

The data in case studies is not uniform; this makes it hard to compare. For example, one study discussed birth weights while another focused on relationships with parents.

This review of studies did include three sets of twins who were found in a method that did not have a selection bias or problems with inconsistent collection of data.

1) Zucker looked at the records of 561 patients who went to a Canadian clinic for gender dysphoria between 1976 and 2011 and found 25 sets of twins. The patients were all under 12 years old.

They found no cases where both twins had gender dysphoria.

2) Heylens and De Cuypere looked at 3 sets of adult twins from the 450 patients who went to a Belgian gender clinic between 1985-2011 plus 3 sets of non-adult twins who went to the Belgian gender clinic for children and teenagers.

They found only one case where both of the twins had gender dysphoria: a set of identical twins who were female-to-male transgender (FtM).

3) Vujovic et al reviewed all the cases of gender dysphoria who were treated at a Serbian clinic between 1987 and 2006. Out of 147 people, one trans man and one trans woman had a fraternal twin. Neither of their twins had gender dysphoria.

If we exclude case studies because of possible bias, we end up with no genetic component to gender dysphoria in trans women. None of the clinics found pairs of male twins who both had gender dysphoria.

The problem with this approach is that identical twins who are both male-to-female transsexuals exist. They just didn’t show up at these three clinics. Presumably, they are very rare.

Using the clinic studies for trans men we would have one set of identical Belgian twins who both had gender dysphoria, and one set of identical Canadian twins who did not. In addition, we would have three sets of fraternal twins where only one twin had gender dysphoria. This is not enough data.

So it makes sense to look at the data from individual case studies; we just need to be cautious about interpreting it. It is possible that it would over or underestimate the genetic component to gender dysphoria.

What was the data, then?

The authors searched the literature and put their data from the three clinics together with data from 17 different case reports and studies.***

They found:

FtMs with identical twins

3 sets of identical twins who both had gender dysphoria (37.5%)

5 sets of identical twins where only one of the twins had gender dysphoria (62.5%)

FtMs with fraternal twins

5 sets of fraternal twins where only one of the twins had gender dysphoria (100%)

MtFs with identical twins

6 sets of identical twins where both twins had gender dysphoria (40%)

9 sets of identical twins where only one twin had gender dysphoria (60%)

MtFs with fraternal twins

16 sets of fraternal twins where only one twin had gender dysphoria (100%)

Based on this data, identical twins with gender dysphoria are more likely than fraternal twins or the general public to have a twin with gender dysphoria. This suggests a genetic component to gender dysphoria.

However, most of the time, only one identical twin has gender dysphoria. This suggests other factors are involved in gender dysphoria.

At this point, we have no idea what the other factors involved might be. The case reports don’t give enough information on the twins to figure it out. The information they give is inconsistent; one study reported on the age of the first period while another talked about whether or not the mother was domineering. In addition, we may be comparing apples and oranges; for example, one study looked at an adult male American Indian in 1976, another looked at 13 year old American females in 1992.

The authors of the review conclude:

“The etiology of GID is a complex process of biopsychosocial components with unexplained interactions. Twin literature on GID supports the contribution of genetic factors to the development of gender identity with a higher tendency in males than in females.****

Since sample size is still limited and genotype studies are lacking, conclusions must be drawn with caution.

Therefore, detailed registers of GID twins, preferably on MZ twins discordant for GID and DZ twins are needed, to gain more decisive information about the influence of genetic vs. environmental factors in the development of GID.

The authors of the study combine the data from studies of MtF and FtM twins for the statistical analysis. This gives them 9 pairs of identical twins where both twins had gender dysphoria (39%) and 14 pairs of identical twins where only one twin had gender dysphoria (61%). This is contrasted with 21 sets of fraternal twins where only one twin had gender dysphoria (100%). The difference is statistically significant.

This might be problematic since the mechanism that causes gender dysphoria in trans women is probably different from the mechanism that causes gender dysphoria in trans men. The genes are also probably different.

On the other hand the question here is whether or not gender dysphoria is inheirited, so perhaps this works.

Another problem is the possibility of selection bias. It looks like people are over-reporting cases involving identical twins. This might affect comparisons between identical twins and fraternal twins.

In addition, the total size of the group used in their statistical analysis is small and includes disparate groups – males and females, adults and children, people in different countries, and people living in different eras.

In the end, we’re left with weak evidence for a genetic component to gender dysphoria. We can’t prove it, but there is an excellent case for doing more studies in this area.

There is also an excellent case for future studies looking at what factors make one identical twin have gender dysphoria and one not. This seems to be the more common outcome than for both twins to have gender dysphoria.*****

Original Review:

Gender Identity Disorder in Twins: A Review of the Case Report Literature by Heylens G, De Cuypere G, Zucker KJ, Schelfaut C, Elaut E, Vanden Bossche H, De Baere E, T’Sjoen G in J Sex Med. 2012 Mar;9(3):751-7.


*Authors of the studies were from Belgium, Canada, Germany, Iran, Israel, the Netherlands, Serbia, Switzerland, the United Kingdom, and the United States. In addition, one author seemed to be from Scandinavia, possibly either Norway or Sweden.

**Using IVF means that the parents were infertile. It might be that the parents were older or that they had something wrong with their reproductive systems. It could be that the parent’s age or fertility problems affected the children rather than the IVF procedure.

***In some cases, it is hard to tell from the title if an article was a study or case report or an article on gender dysphoria that includes information on a case. Then again, the sub-title of this study is “A review of the case report literature,” so maybe they were all case reports.

**** I think the idea that there is a higher tendency in males than females is overstated. There were only 8 pairs of identical FtM twins and I doubt the 2.5% difference in the frequency of FtM versus MtF identical twin pairs who both have gender dysphoria is significant.

***** There may be selection bias in the cases of identical twins from the case reports. However, the clinic studies did find six sets of identical twins. In five of these six pairs, only one twin had gender dysphoria. Specifically, they found four pairs of identical male twins where only one twin had gender dysphoria, one pair of identical female twins where only one twin had gender dysphoria, and one pair of identical twins who were both FtM. So it looks like it is more common for only one identical twin to have gender dysphoria.

Emphases added are mine, including in the quote from the original review of the literature.

Prenatal exposure to anticonvulsants and psychosexual development

This is a 1999 study with intriguing results.

The authors followed-up on 243 people who were exposed to phenobarbital and/or phenytoin before they were born.

Three of them had medically and socially transitioned; two trans men (born female) and one trans woman (born male).*

Among the 147 people who they were able to speak to, the authors also found three possible cases of gender dysphoria.

One woman had had cross-gender feelings from childhood until age 21 when she became pregnant.

Another woman “did not feel very comfortable with her femininity, but had made the conscious decision to ‘to behave like a woman.'”

Finally one of the men “denied the changes his body had undergone during puberty. He claimed to have a female’s voice (although the researcher heard a male voice), he denied having facial hair (although he had a moustache), and he denied having erections.”

There were also two gay men among the people they interviewed.

The authors looked at a control group of people born at their hospital during the same time period (1957-1972). None of them had transitioned, none of them reported gender dysphoria, and none of them were gay.

In addition, the authors compared the number of trans people in their sample to the general population in the Netherlands and the difference was statistically significant.

Clearly, something is going on here.

Why hasn’t anyone followed up on this? Well, for one thing, phenobarbital and phenytoin are no longer given to pregnant women. We don’t need to worry about any possible risks from people taking them. Besides, it would be hard to find people born recently who had been exposed to phenobarbital before birth.

On the other hand, the results suggest that it may be worth looking for connections between gender dysphoria and medications mothers take during pregnancy.

The authors of the study theorized that in order to metabolize the anti-convulsants, the fetus would produce microsomal enzymes in its liver. Then, “these enzymes also catabolize steroid hormones so that the steroids cannot properly exert their action on brain and body.”

This would suggest that prenatal hormones were involved in developing gender dysphoria.

It might be, however, that the medications themselves affected the babies.  Both phenobarbital and phenytoin are known to cause fetal abnormalities.

It could also be that the medications affected the mothers’ eggs rather than affecting the baby.

If the mothers breastfeed the babies and continued to take the drugs, they might have affected the babies’ development after birth.

Another factor to consider is that phenytoin may cause babies to develop ambiguous genitals. That in turn might affect how children are raised, including the possibility of being raised as a sex different from your genetic sex. It would be useful to know if any of the people in the study had ambiguous genitals.

It’s also possible that the drugs themselves weren’t the issue here. The mothers were taking the drugs for a reason. Could the mothers have passed on genes related to epilepsy or emotional problems that also affected gender identity? Could being raised by a mother with epilepsy or emotional problems affect gender dysphoria?

In this study, one of the trans men had a mother with epilepsy; the mothers of the other trans man and the trans woman did not. It’s not clear from the article if the two non-epileptic mothers took phenobarbital for emotional problems or pregnancy-related complaints.

There’s no information given on the mothers of the three people who did not transition but had some symptoms of gender dysphoria.

This is not strong evidence of a link between epilepsy and gender dysphoria, but it might be worthwhile for someone to do a study looking at epilepsy in the families of people with gender dysphoria.

We don’t know anything about the non-epileptic mother of the trans man as the trans men did not participate in the follow-up interviews.

However, among the people the authors interviewed, cross-gender behavior was not related to parental psychiatric problems, family problems during childhood, or socioeconomic status. This should not be surprising – cross-gender behaviors are not a problem. They are also not the same thing as gender dysphoria.

Which leaves us where we started: it is possible that something about the mothers or their genes affected the children who developed gender dysphoria.

The study provides some other evidence about exposure to the medications and psychosexual development. The authors interviewed 147 people in depth and looked at other possible traits that might have been influenced if the prenatal hormones were abnormal. This group did not include the two trans men, but it did include the trans woman and the three people with some symptoms of gender dysphoria.

They did not find statistically significant differences between the people exposed to anti-convulsants and the controls in gender role behavior in childhood or adulthood, sexual orientation,** physical development during puberty, feelings about puberty, adult satisfaction with secondary sex characteristics, or experience of their first sexual activities.

In general, the overall psychosexual development of people exposed to the anti-convulsants prenatally was not different from the people who were not exposed.

They did find, however, that there were more people in the group exposed to anti-convulsants who had high cross-gender behavior scores than in the control group. In other words, the group averages were comparable, but there were more people who were very gender non-conforming in the group that had been exposed to anti-convulsants.

So did the pre-natal hormones matter? We still don’t have the answer.

It could be that the anti-convulsants only affected some babies’ hormones. It could be that they affected the hormones, but that this isn’t enough to cause gender dysphoria in most people; perhaps the environment plays a role. It could be that the hormones are irrelevant and the medications directly affected the babies or the mothers’ eggs. It could be that something about the mothers who needed to take medications was different and affected their children.

What we do know is that taking these medications was linked to developing gender dysphoria severe enough for people to transition.

It’s a result worth some new research – does exposure to other medications affect gender dysphoria? does it matter if the father is exposed to the medication? are there any links between epilepsy and gender dysphoria?

Original Article:

Prenatal exposure to anticonvulsants and psychosexual development by Dessens AB, Cohen-Kettenis PT, Mellenbergh GJ, vd Poll N, Koppe JG, Boer K. in Arch Sex Behav. 1999 Feb;28(1):31-44.



*Some details about the transitioners:

The trans woman was exposed to phenobarbital during weeks 18-40 gestational age and one of the trans men was exposed to it during weeks 36-42.  Their mothers did not have epilepsy. They authors don’t mention the dose they took, but earlier they say that mothers who didn’t have epilepsy generally took a lower dose.

The other trans man was exposed to phenobarbitol, phenytoin, and amphetamines throughout the pregnancy. His mother had epilepsy.

All three of them started hormone therapy at age 18-23 and had sex reassignment surgery at 20-25. The trans woman had identified as a girl since early childhood; the authors did not have data on the trans men.

**However for sexual orientation in males, the p-value was 0.07 which is close to statistically significant. (There were two gay men in the group exposed to anti-convulsants and none in the control group.)

Desisting and persisting gender dysphoria after childhood: A qualitative follow-up study – Review, Part I

This is a fascinating study of a group of children with gender dysphoria. The authors interviewed them as teenagers when some of them had lost their gender dysphoria and some of them had not.

Most children diagnosed with gender dysphoria do not go on to transition; their gender dysphoria goes away. Gender dysphoria faded at puberty for 84% of the children in previous follow-up studies.*

In this study, the authors identified 53 Dutch speaking teenagers that their clinic had diagnosed with gender identity disorder before age 12.** Among these 53 teenagers, 55% had reapplied to the clinic for transition while 45% had not. The authors do not address the question of why their patients were more likely to still have gender dysphoria than in past studies.***

The authors interviewed only 25 of the 53 teenagers; 14 teenagers who applied for sex reassignment (7 male and 7 female) and 11 who did not (6 male and 5 female). They say that:

All adolescents were approached, orally or in writing, to participate in the study. Based on the principle of saturation in information (Glaser & Strauss, 1967), 25 adolescents were interviewed.

This limits the conclusions that can be drawn from the data, however, this is a qualitative study. It uses interviews to explore the development of gender dysphoria in these teenagers. This allows the authors to find directions for future research.****

Based on their interviews with the teenagers the authors found:

1. There were no differences in childhood behavior between the group that lost their gender dysphoria and the group that did not.

2. Both groups identified as the other gender as children, but when they were interviewed as teenagers, they explained it differently.

3. Both groups were uncomfortable with their bodies as children, but they explained it differently as teenagers.

4. The teenagers who requested transition were all attracted to people of their natal sex while the teenagers who no longer had gender dysphoria were mostly attracted to the opposite sex.

5. The years 10-13 were critical in the children’s development; this was when they either lost their gender dysphoria or became more dysphoric.

6. Important factors related to the development of adolescent feelings about gender were: changes in the social environment, the physical development of their bodies at puberty, and falling in love and discovering their sexual orientation.

7. For some of the girls whose gender dysphoria had faded, it was hard to transition back because they had worn boys’ clothing and been perceived as boys.

8. One of the teenagers they interviewed felt half female, half male. He did not want to transition.

The authors of the study conclude:

“Based on the significance most adolescents attribute to the period between 10 and 13, we suggest that clinicians should concentrate clearly on what happens in this phase of development.

It is recommended to specifically address the adolescents’ feelings regarding the factors that came up as relevant in our interviews (i.e. the effects of the changing social environment, the response to anticipated or actual puberty, and the emerging romantic/sexual feelings and sexual partner choice), before any medical steps are taken (e.g. to suppress further pubertal development).

As for the clinical management of children before the age of 10, we suggest a cautious attitude towards the moment of transitioning. Given our finding that some girls, who were almost (but not even entirely) living as boys in their childhood years, experienced great trouble when they wanted to return to the female gender role, we believe that parents and caregivers should fully realize the unpredicatability of their child’s pychosexual outcome.

They may help their child to handle their gender variance in a supportive way, but without taking social steps long before puberty, which are hard to reverse. This attitude may guide them through uncertain years without the risk of creating the difficulties that would occur if a transitioned child wants to return to his/her original gender role.”

(Paragraphs and bold added by George Davis.)

Short version: Children should probably not transition socially before age 10. Parents and teachers should understand that the children may lose their gender dysphoria.

Therapists should work carefully with children who have gender dysphoria in the years between 10 and 13. Before giving them puberty blockers therapists should address the teenagers’ feelings about changing social relationships, puberty, and sexual development.

End of Part I of the Review of this study.

Original Article:

Desisting and persisting gender dysphoria after childhood: a qualitative follow-up study by Steensma TD, Biemond R, de Boer F, Cohen-Kettenis PT in Clin Child Psychol Psychiatry. 2011 Oct;16(4):499-516

*The studies the authors cite followed a total of 246 children; only 39 of them had gender dysphoria after puberty, thus the overall persistence rate for the dysphoria was 16%. The persistence rate varied among the different studies from 2% to 27% (i.e. 73%-98% of the children stopped having gender dysphoria).

**The teenagers in the study were chosen from a total of 198 children who applied to their clinic between 2000-2007. The rest of the children did not meet the criteria for the study, although the authors don’t say if this was due to not being a teenager at the time of the study, not being diagnosed with GID, or not speaking Dutch.

***A few possibilities would be: a difference in the therapy given to the children (some therapies might be more effective than others), cultural differences in the countries where the studies were done (some cultures might make it harder to be gender non-conforming while others might make it easier to transition), a difference in the diagnostic methods (perhaps this clinic did a better job of diagnosing gender dysphoria), cultural differences in different eras, environmental differences in different eras (perhaps hormones are affecting children more now), or something about the way this study chose the 53 teenagers (this seems unlikely).

****A more serious question is that the authors do not say if they heard back from all of the teenagers they contacted. They cannot be sure that all of the teenagers who did not request further treatment were no longer dysphoric if they did not speak to them. This does not effect the results of their interviews, but it is an important issue.

Transgender Feminization of the Facial Skeleton – Review

This is a discussion of facial feminization surgeries performed on 35 trans women between 1992 and 1996. The surgeries seem to have been done at the Free University Hospital of Amsterdam. Based on the dates and the photos, this study includes the 16 individuals discussed in an earlier article.

Forty-six patients with GID were referred for possible surgery; of these “In 11 cases, patients’ expectations and surgical possibilities did not match,” so they did not have any surgery.

The authors provide in-depth information on the different surgeries they used and how they work.

As in the earlier study, the patients were happy and felt that the surgeries had made them appear more feminine, but the patients had also changed in other ways at the same time.

Once again, it is hard to judge from the before and after pictures because the patients often have different hair-dos, etc. In some cases, the patients look like they might pass before surgery.

The authors conclude:

there is a need for a more objective standardization of the differences in the facial features of the two sexes, to facilitate surgical treatment planning and more objectively assess the outcome of the facial surgery on psychosocial functioning and appearance, not only from the perspective of those treating, but also from the patient’s own point of view.

Original Article:

Transgender Feminization of the Facial Skeleton by Alfred G. Becking, MD, DDS, PhD,  D. Bram Tuinzing, DDS, PhD, J. Joris Hage, MD, PhD, Louis J.G. Gooren, MD, PhD

Note: This article contains photos of surgery.