Finger-length ratio (2D:4D) and early infant development

The Relationship Between Digit Ratio and Motor Development and Sensory Processing in Infants

Observational Nigde Omer Halisdemir University · NCT07525726

This project will test whether babies' finger-length ratio (2D:4D) is linked to motor skills and sensory processing in term infants aged 12–18 months.

Quick facts

Study typeObservational
Enrollment80 (estimated)
Ages12 Months to 18 Months
SexAll
SponsorNigde Omer Halisdemir University Academic / other
Locations1 site (Niğde)
Trial IDNCT07525726 on ClinicalTrials.gov

What this trial studies

This observational study will measure the second-to-fourth finger length ratio (2D:4D) in term infants aged 12–18 months and compare those measurements with standardized tests of motor development and sensory processing. Researchers will enroll healthy, term infants and exclude those with preterm birth, genetic or metabolic disorders, intrauterine growth restriction, or a history of hand surgery. Measurements will be taken in person at the university site, combining simple finger length measurements with established developmental screening or assessment tools. The goal is to describe any associations between a putative marker of prenatal androgen exposure and early motor and sensory outcomes.

Who should consider this trial

Good fit: Ideal candidates are healthy term infants (born 37–40 weeks) who are 12–18 months old, without major congenital, neurological, metabolic, or genetic diagnoses and whose parents agree to participate.

Not a fit: Preterm infants, those with known genetic, neurological, metabolic conditions, intrauterine growth restriction, or a history of hand surgery are excluded and unlikely to benefit from the findings of this study.

Why it matters

Potential benefit: If a clear link is found, 2D:4D could serve as an early, noninvasive marker to help identify infants who might benefit from closer monitoring or early developmental support.

How similar studies have performed: Previous research supports 2D:4D as a marker of prenatal sex hormone exposure in older children and adults, but direct links between 2D:4D and early infant motor or sensory outcomes are limited and not yet well established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Term infants (37-40 weeks),
* Infants aged 12-18 months

Exclusion Criteria:

* Preterm infants,
* Infants with congenital infections or proven genetic changes,
* Infants and mothers diagnosed with metabolic, neurological, and genetic diseases,
* Maternal diabetes,
* Intrauterine growth retardation,
* Infants with a history of hand-related surgery,
* Children whose parents did not volunteer to study

Where this trial is running

Niğde

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Infant Developmental Assessmentmotor developmentsensory processing2D:4D ratiodigit ratioinfantPrenatal androgen
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.