Prenatal Androgen and Skills

May 30, 2026 updated by: Rabia ZORLULAR, Nigde Omer Halisdemir University

Prenatal Androgen and Fine Motor Skills and Tactile Discrimination

Due to the difficulties and risks of directly measuring prenatal hormone levels, biomarkers that indirectly reflect this exposure are used in research. In this context, the ratio of second to fourth finger length (2D:4D) is widely preferred because it is an easily applicable and non-invasive measurement. Evidence shows that 2D:4D stabilizes from the second trimester of pregnancy onward and exhibits strong sex differences across populations. The 2D:4D ratio is generally lower in men than in women. 2D is more strongly influenced by prenatal estrogen, while 4D is more strongly influenced by prenatal testosterone; this occurs during the first trimester of intrauterine fetal development. To our knowledge, studies examining the relationship between the 2D:4D ratio, an indirect indicator of prenatal androgen exposure, and dexterity and tactile discrimination are limited. Accordingly, the planned study aims to evaluate the relationship between the 2D:4D ratio and fine motor skills and tactile discrimination in healthy young adults.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Sex hormones experienced during prenatal exposure play a significant role in shaping certain lifelong characteristics by influencing both the physical and neurological development of individuals. The effects of these hormones, particularly on the developing nervous system, contribute to the emergence of behavioral and functional differences. Hand preference and certain behavioral traits in humans have been shown to be related to prenatal hormonal exposure. However, the development of these traits is not limited to hormonal influences alone, but is shaped by the interaction of genetic, environmental, and sociocultural factors. Due to the difficulties and risks of directly measuring prenatal hormone levels, biomarkers that indirectly reflect this exposure are used in research. In this context, the ratio of second to fourth finger length (2D:4D) is widely preferred because it is an easily applicable and non-invasive measurement. The 2D:4D ratio is generally lower in men than in women. 2D is more strongly influenced by prenatal estrogen, while 4D is more strongly influenced by prenatal testosterone; this occurs during the first trimester of intrauterine fetal development. However, whether the 2D:4D ratio is a reliable indicator of prenatal hormonal exposure is still a controversial issue in the literature. Therefore, examining the relationship between the 2D:4D ratio and various biological and functional characteristics remains important. To our knowledge, studies examining the relationship between the 2D:4D ratio, an indirect indicator of prenatal androgen exposure, and dexterity and tactile discrimination are limited. Accordingly, the planned study aims to evaluate the relationship between the 2D:4D ratio and fine motor skills and tactile discrimination in healthy young adults. It is hypothesized that prenatal hormonal exposure may indirectly shape finger morphology and receptor distribution by affecting skin and nervous system development, which may be a determining factor in tactile sensitivity and dexterity.

Study Type

Observational

Enrollment (Estimated)

94

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
    • Merkez
      • Niğde, Merkez, Turkey (Türkiye)
        • Nigde Omer Halisdemir University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

- Healthy individuals aged 18-40

Description

Inclusion Criteria:

  • Healthy individuals aged 18-40
  • Having sufficient visual and auditory function to understand and administer the test,
  • Voluntary agreement to participate in the study and providing informed consent.

Exclusion Criteria:

  • Individuals with any musculoskeletal pathology,
  • History of upper extremity trauma,
  • Individuals diagnosed with metabolic, neurological, or genetic diseases,
  • Individuals with a history of hand surgery within the last 6 months,
  • Pregnancy or breastfeeding.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Healthy adults
Young and healthy adults aged 18-40
Other: Digit Ratio
The second (2D) and fourth (4D) finger lengths of the participants will be measured separately in both hands by a physiotherapist with over thirteen years of clinical experience.
Behavioral: Fine motor skills
Hand dexterity will be assessed using the Purdue Pegboard Test. The test will be administered according to standard procedure with participants seated at a table. Participants will be asked to place the pegs into the corresponding holes as quickly and accurately as possible within a specified time (30 seconds).
Behavioral: Tactile Discrimination
To perform the 2-point discrimination tests, the Baseline® two-point discriminator will be used. Measurements will be applied to the distal phalangeal pulp of the index finger on both hands while participants are seated in a comfortable position with their eyes closed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
2-point discrimination test
Time Frame: 12 months
To perform 2-point discrimination tests, the Baseline® two-point discriminator will be used. Measurements will be applied to the distal phalangeal pulp of the index finger on both hands while participants are seated in a comfortable position with their eyes closed. The test will begin at a distance of 8 mm, allowing participants to perceive the stimulus as two points, and then the distance will be gradually reduced. After 5 mm, measurements will continue at 1 mm intervals. In each application, both contact points will be applied to the skin simultaneously and with equal pressure, and participants will be asked to indicate whether the perceived stimulus is a single point or two points.
12 months
Digit Ratio
Time Frame: 12 months

Measurements will be taken after participants' hands are placed on a flat surface with palms facing upwards. Finger length is defined as the distance from the midpoint of the proximal crease line where the finger joins the palm to the distal point of the fingertip.

Measurements will be performed using a digital caliper with 0.01 mm accuracy, two separate measurements will be taken for each finger, and the average value will be recorded. Based on the obtained measurements, the 2D:4D finger ratio will be calculated by dividing the 2D length by the 4D length in both hands .
12 months
Fine motor skills
Time Frame: 12 months
The test will be administered according to standard procedure while participants are seated at a table. Participants will be asked to place the pegs into the corresponding holes as quickly and accurately as possible within the specified time (30 seconds). In the dominant and non-dominant hand tests, participants will be asked to place pegs with one hand for 30 seconds, while in the both-hand test, the simultaneous use of both hands will be evaluated. The number of correctly placed pegs for each subtest will be recorded, and higher scores will be considered as better fine motor skill performance.
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nigde Omer Halisdemir University

Investigators

  • Principal Investigator: Rabia ZORLULAR, Nigde Omer Halisdemir University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

May 30, 2026

First Submitted That Met QC Criteria

May 30, 2026

First Posted (Actual)

June 4, 2026

Study Record Updates

Last Update Posted (Actual)

June 4, 2026

Last Update Submitted That Met QC Criteria

May 30, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Androgen and Skills

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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