Anogenital Distance Differences Between Transgender Males and Female Individuals

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).

Study Overview

• Status: Unknown
• Conditions: Sexual Orientation Conflict Disorder
• Intervention / Treatment: Other: Anogenital distance measurement

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.

• Study Type: Observational
• Enrollment (Anticipated): 150

Contacts and Locations

• Study Contact: Name: Adnan Orhan, M.D.; Phone Number: +90 505 6337102; Email: dr.adnan.orhan@hotmail.com
• Study Contact Backup: Name: Ebru Sakar, M.D.; Phone Number: +90 507 8517109; Email: ebru_sakar@hotmail.com

Study Locations

• Turkey
  • Ozluce
    • Bursa, Ozluce, Turkey, 16059
      • Recruiting
      • Uludag University Hospital, Department of Obstetrics and Gynecology
      • Contact: Adnan Orhan, M.D.; Phone Number: +90 505 6337102; Email: dr.adnan.orhan@hotmail.com
      • Contact: Ebru Sakar, M.D; Phone Number: +90 507 8517109; Email: ebru_sakar@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

The study population will be healthy transgender male individuals whose gender identity (Male) are different from their birth-assigned sex (Female). These individuals are healthy biologically female persons and want to change their gender to male status. In Turkey, if a woman wants to change her gender, she has to bring a lawsuit against the birth registration office to change her gender to male status. Medico-legal assessments then have to be made at a tertiary gynecological center through the court. The participants will be invited to the study at the time of medico-legal evaluation before the sex reassignment surgery.

Description

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)

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Transgender Male individuals; Group Description: This group consists of transgender male individuals who come to the gynecology clinic for medico-legal evaluation before the sex reassignment surgery.; Intervention: Anogenital distance measurement with a digital caliper in centimeters in the lithotomy position.	Other: Anogenital distance measurement; 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.
Normal healthy female individuals; Group Description: Healthy women with normal sexual orientation.; Intervention: (The same) Anogenital distance measurement with a digital caliper in centimeters in the lithotomy position.	Other: Anogenital distance measurement; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anogenital Distance (Anus-Clitoris)	Anogenital Distance (Anus-Clitoris) will be measured from the anterior clitoral surface to the centre of the anus with a digital caliper in centimeters.	1 hour
Anogenital Distance (Anus-Posterior Fourchette)	Anogenital Distance (Anus-Posterior Fourchette) will be measured from the posterior fourchette to the centre of the anus with a digital caliper in centimeters.	1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anti-Mullerian Hormone (AMH) level measurement	All blood samples will be collected in the morning after the patient has fasted for at least 8 hours.	8 hours
FSH (Follicle-stimulating hormone), LH (Luteinizing hormone), Estradiol, and Testosteron level measurements	All blood samples will be collected in the morning after the patient has fasted for at least 8 hours.	8 hours

Collaborators and Investigators

• Sponsor: Uludag University
• Investigators: Study Director: Adnan Orhan, M.D., Uludag University, Department of Obstetrics and Gynecology

Publications and helpful links

General Publications

• Wu Y, Zhong G, Chen S, Zheng C, Liao D, Xie M. Polycystic ovary syndrome is associated with anogenital distance, a marker of prenatal androgen exposure. Hum Reprod. 2017 Apr 1;32(4):937-943. doi: 10.1093/humrep/dex042.
• Sanchez-Ferrer ML, Mendiola J, Hernandez-Penalver AI, Corbalan-Biyang S, Carmona-Barnosi A, Prieto-Sanchez MT, Nieto A, Torres-Cantero AM. Presence of polycystic ovary syndrome is associated with longer anogenital distance in adult Mediterranean women. Hum Reprod. 2017 Nov 1;32(11):2315-2323. doi: 10.1093/humrep/dex274.

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2019
• Primary Completion (Anticipated): February 15, 2020
• Study Completion (Anticipated): March 15, 2020

Study Registration Dates

• First Submitted: December 26, 2018
• First Submitted That Met QC Criteria: December 26, 2018
• First Posted (Actual): December 28, 2018

Study Record Updates

• Last Update Posted (Actual): April 2, 2019
• Last Update Submitted That Met QC Criteria: March 31, 2019
• Last Verified: March 1, 2019

More Information

Terms related to this study

• Keywords: transgender males; anogenital distance
• Other Study ID Numbers: UU-SUAM-2017-21/37

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: De-identified individual participant data for all primary and secondary outcome measures will be made available.
• IPD Sharing Time Frame: Data will be available within 9 months of study completion.
• IPD Sharing Access Criteria: Data access requests will be reviewed by an external independent review panel. Requestors will be required to sign a data access agreement.
• IPD Sharing Supporting Information Type: Study Protocol; Informed Consent Form (ICF)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No