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Anogenital Distance Differences Between Transgender Males and Female Individuals

Anogenital Distance Differences Between Transgender Males and Female Individuals

Status
UNKNOWN
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03789331
Enrollment
150
Registered
2018-12-28
Start date
2019-04-01
Completion date
2020-03-15
Last updated
2019-04-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Sexual Orientation Conflict Disorder

Keywords

transgender males, anogenital distance

Brief summary

This study evaluates the anogenital distance measurement differences between transgender male individuals and normal healthy female individuals. Half of the participants will be selected from the men with a masculine gender identity who were assigned female sex at birth (Woman who wanted to be a man). Transgender men will be evaluated with the vaginal examination, and anogenital distance will be measured at the time of gynecological medico-legal evaluation before the sex reassignment surgery. While the other half of the participants will be selected from healthy female individuals, ordinary healthy women will be selected from patients who come to the gynecology clinic for another reason (Women with normal sexual orientation).

Detailed description

There is considerable evidence in human beings and in animal models supporting that anogenital distance as a sensitive biomarker of prenatal androgen reflection of reproductive health and sexual orientation. Anogenital distance is approximately twice as long in male animals compared to female animals, and it is routinely used to determine the natal or birth-assigned sex. Studies have shown alterations in anogenital distance associated with reproductive health and sexual orientation. For instance, shorter anogenital distance has been reported in boys with hypospadias and cryptorchidism. Men with reduced testicular volume have significantly shorter anogenital distance compared with controls. Increased anogenital distance has been indicated in girls with congenital adrenal hyperplasia. The investigators hypothesized that a prenatal pathological androgenic environment, resulting in a longer anogenital distance, will be able to be associated with a higher risk of sexual orientation disorders like transsexualism. This cross-sectional study aimed to assess the anogenital distance measurement differences between transgender male persons and normal healthy female individuals.

Interventions

The women were kindly asked to lay down in the lithotomy position with their thighs at 45° to the examination table. A digital caliper (Mitutoyo 500-752-10 ABSOLUTE Digimatic Coolant Proof Caliper 0-150mm / 0-6, Mitutoyo Corporation, Japan) was used to measure anogenital distance. Anogenital distance anus to clitoris: will be measured in centimeters from the anterior clitoral surface to the center of the anus. Anogenital distance anus to fourchette: will be measured in centimeters from the posterior fourchette to the center of the anus. Two investigators who were blind to the gynecological status of the women will measure each distance three times, and the mean value of the six measurements of each anogenital distance will be used.

Sponsors

Uludag University
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
CROSS_SECTIONAL

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
Yes

Inclusion criteria

* Individuals who are 18-50 years old. * Healthy transgender male individuals whose gender identity (Male) are different from their birth-assigned sex (Female). The participants will be invited to the study at the time of medico-legal evaluation before the sex reassignment surgery.

Exclusion criteria

* Individuals who are older than 50 (People older than 50 cannot change their gender legally in Turkey). * Other sexual orientation disorders. (Lesbian, Gay, Bisexual, Queer, Intersex, or Asexual persons)

Design outcomes

Primary

MeasureTime frameDescription
Anogenital Distance (Anus-Clitoris)1 hourAnogenital Distance (Anus-Clitoris) will be measured from the anterior clitoral surface to the centre of the anus with a digital caliper in centimeters.
Anogenital Distance (Anus-Posterior Fourchette)1 hourAnogenital Distance (Anus-Posterior Fourchette) will be measured from the posterior fourchette to the centre of the anus with a digital caliper in centimeters.

Secondary

MeasureTime frameDescription
Anti-Mullerian Hormone (AMH) level measurement8 hoursAll blood samples will be collected in the morning after the patient has fasted for at least 8 hours.
FSH (Follicle-stimulating hormone), LH (Luteinizing hormone), Estradiol, and Testosteron level measurements8 hoursAll blood samples will be collected in the morning after the patient has fasted for at least 8 hours.

Countries

Turkey (Türkiye)

Contacts

Primary ContactAdnan Orhan, M.D.
dr.adnan.orhan@hotmail.com+90 505 6337102
Backup ContactEbru Sakar, M.D.
ebru_sakar@hotmail.com+90 507 8517109

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026