Infant Developmental AssessmentNCT07525726
The Relationship Between Finger Ratio and Development in Infants
An observational study of Infant Developmental Assessment, run by Nigde Omer Halisdemir University at 1 site in Turkey (Türkiye).
Trial summary
One of the most prominent indicators of prenatal androgen exposure is considered to be the ratio of second and fourth finger lengths (2D:4D). The 2D:4D finger ratio refers to the ratio of the length of the second finger (2D; index finger) and the fourth finger (4D; ring finger). Read more about this study
- Who is it for?
- Ages 12 to 18 monthsHealthy volunteers can take part
- Conditions the study is for
- Infant Developmental Assessment
- What is being tested?
- Digit Ratio, Motor development and Sensory processing functions
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 80 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 6 Apr 2026to 1 Apr 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 to 18 months
- All sexes
- Healthy volunteers accepted
- Child
Study population: The study will include healthy, full-term (37-40 weeks of gestation) infants aged 12 to 18 months.
Who may be able to join
- Term infants (37-40 weeks),
- Infants aged 12-18 months
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Rabia Zorlular contact
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Nigde Omer Halisdemir University
Niğde
Rabia ZORLULAR, +5424362082, rabiaeraslan118@gmail.com
About this study
Official title: The Relationship Between Digit Ratio and Motor Development and Sensory Processing in Infants
One of the most prominent indicators of prenatal androgen exposure is considered to be the ratio of second and fourth finger lengths (2D:4D). The 2D:4D finger ratio refers to the ratio of the length of the second finger (2D; index finger) and the fourth finger (4D; ring finger). Evidence suggests that 2D:4D is developmentally stable and stabilizes from the second trimester of pregnancy. It has been reported that the 2D:4D ratio correlates positively with estrogen and negatively with testosterone. In both sexes, prenatal testosterone levels are inversely related by a 2D:4D ratio, which does not change with age. Androgens can have direct trophic effects on target cells or indirectly affect neuronal growth through neurotrophic mediators released locally by steroid-sensitive neuronal or glial cells. Prenatal testosterone can have long-term organizational effects on the structure and function of various body systems (e.g., cardiovascular and musculoskeletal systems) that are important for physical activity and exercise.
Read the detailed description
One of the most prominent indicators of prenatal androgen exposure is considered to be the ratio of second and fourth finger lengths (2D:4D). The 2D:4D finger ratio refers to the ratio of the length of the second finger (2D; index finger) and the fourth finger (4D; ring finger). Evidence suggests that 2D:4D is developmentally stable and stabilizes from the second trimester of pregnancy. It has been reported that the 2D:4D ratio correlates positively with estrogen and negatively with testosterone. In both sexes, prenatal testosterone levels are inversely related by a 2D:4D ratio, which does not change with age.
From a gender perspective, differences have been found in the basic motor skills of boys and girls. Boys have greater object control skills than girls. Gender is one of the most studied variables in motor development. Many longitudinal studies show that boys perform better in gross motor skills such as running and jumping, while girls are more successful in fine motor tasks such as drawing or manipulating small objects. Sensory processing involves the capacity to receive, interpret, organize, and respond to sensory input from both one's own body and the external environment. Sensory processing disorders can be observed in infants due to the immaturity of their systems. There are very few studies on measuring finger length in the early stages of newborns. To our knowledge, the relationship between intrauterine androgen exposure (2D:4D) and motor development and sensory processing has not yet been investigated. Therefore, the planned study aims to evaluate the 2D:4D finger ratio in 12-18-month-old infants and to examine the relationship between this ratio and motor development and sensory processing.
- Conditions
- Infant Developmental Assessment
- Being tested
- Digit Ratio, Motor development, Sensory processing functions
- Keywords
- motor development, sensory processing, 2D:4D ratio, digit ratio, infant, Prenatal androgen
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Digit RatioBehavioural
The lengths of the second (2D) and fourth (4D) fingers will be measured separately on each hand. Measurements will be taken with the baby's hands placed flat on a surface with palms facing upwards. Finger length will be defined as the distance from the midpoint of the proximal crease at the base of the finger to the distal end of the finger. A digital caliper with a precision of 0.01 mm will be used, and two separate measurements will be taken for each finger, with the average value recorded. Based on these measurements, the 2D:4D finger ratio for each hand will be calculated by dividing the length of the second finger by the length of the fourth finger.
Motor developmentBehavioural
The Peabody Developmental Motor Scale-2 (PDMS-2) is planned to be used to assess motor development. The PDMS-2 test is designed to identify developmental delays in children aged 0-72 months. It is used to evaluate children's motor development with separate tests and rating scales for both gross and fine motor skills.
Sensory processing functionsBehavioural
The Test of Sensory Functions in Infants was planned for use to assess babies' sensory development. The TSFI is frequently used to evaluate the sensory processing functions of infants aged 4-18 months. It is used to determine whether and to what extent a baby has a sensory processing problem. It consists of 24 items. The TSFI requires the baby to be stimulated and interact with various materials. The total score ranges from 0-49, and the test has normative values for different age groups. Although it can be used from the fourth month onwards, the most reliable and valid results are obtained between 7-18 months.
| Study group | Role | What they receive |
|---|---|---|
| Healthy infants | Healthy, full-term (37-40 weeks of gestation) infants aged 12 to 18 months and their families will be invited to participate in the study. Receives: Behavioral: Digit Ratio; Behavioral: Motor development; Behavioral: Sensory processing functions |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sensory processing
The Test of Sensory Functions in Infants is a standardized assessment tool designed to evaluate sensory processing abilities in infants aged 4 to 18 months. The TSFI examines responses across multiple sensory domains, including tactile, vestibular, visual, and oral-motor functions, providing a comprehensive profile of an infant's sensory processing. In the tactile deep pressure response section, it is scored as 0: reverse response, 1: mild defensive response, and 2: integrated response. In the adaptive motor response section, it is scored as 0: no response, 1: disorganized, 2: partial, 3: organized. In the visual-tactile integration section, it is scored as 0: hyperactive, 1: hyporeactive, and 2: normal. The oculomotor test section is scored as 0: no response or poorly integrated, 1: well integrated. Response to vestibular stimulation is scored as 0: adverse response, 1: mild defensive response, and 2: integrated response. The total score ranges from 0 to 49.
Measured: 12-18 months
Motor development
The Peabody Developmental Motor Scales, Second Edition, is a standardized tool used to assess gross and fine motor skills in children from birth to 5 years of age. The assessment comprises six subtests: reflexes, stationary, locomotion, object manipulation, grasping, and visual-motor integration, which together provide a comprehensive evaluation of a child's motor development. It has been widely validated in both typically developing children and those with various developmental disorders, making it a reliable and widely used instrument in pediatric motor assessment. Items are scored with 0, 1, and 2 points. When the child performs the item according to the specified item criteria, 2 points are given. One point is awarded when the behavior occurs, but the criteria for successful performance are not fully met. A score of 0 is given when the child is unable to try the item or does not reveal any skills when he tries it. Results are expressed as raw, standard, or total motor scores.
Measured: 12-18 months
Digit Ratio
The lengths of the second (2D) and fourth (4D) fingers of the participants will be measured separately on each hand. Measurements will be taken with the participants' hands placed flat on a surface with the palms facing upwards. Measurements will be performed using a digital caliper with a precision of 0.01 mm, 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 on both hands. To increase the reliability of the measurements, the assessments will be performed twice by a researcher who is blind to motor development and sensory processing skills.
Measured: 12-18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2026
- Study start6 Apr 2026
- Primary completion1 Apr 2027 (estimated)
- Study completion1 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Infant Developmental AssessmentStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nigde Omer Halisdemir University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rabia ZORLULAR, Nigde Omer Halisdemir University
- Investigators
- Rabia ZORLULAR, Principal investigator, Nigde Omer Halisdemir University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07525726
- Sponsor's protocol ID
- Digit ratio and development
- Status last verified
- Apr 2026
- First submitted
- 6 Apr 2026
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Cay M, Gurel S. The relationship between mothers' second and fourth finger lengths (2D:4D) and anthropometric measurements (height, weight, head circumference, and 2D:4D) of the newborns. Am J Hum Biol. 2022 May;34(5):e23700. doi: 10.1002/ajhb.23700. Epub 2021 Nov 9.
PubMed 34751980Ernsten L, Korner LM, Heil M, Schaal NK. The association between 2D:4D digit ratio and sex-typed play in children with and without siblings. Sci Rep. 2024 Jul 2;14(1):15231. doi: 10.1038/s41598-024-65739-1.
PubMed 38956189Paukner A. Digit ratio (2D:4D) and its behavioral correlates in infant rhesus macaques (Macaca mulatta). Dev Psychobiol. 2020 Nov;62(7):992-998. doi: 10.1002/dev.21917. Epub 2019 Sep 12.
PubMed 31512755
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Relationship Between Digit Ratio and Motor Development and Sensory Processing in Infants
- ClinicalTrials.gov ID
- NCT07525726
- Acronym / sponsor ID
- Digit ratio and development
- Conditions
- Infant Developmental Assessment
- Keywords
- motor development, sensory processing, 2D:4D ratio, digit ratio, infant, Prenatal androgen
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Nigde Omer Halisdemir UniversityUniversity, hospital or other
- Study start
- 6 Apr 2026 (actual)
- Primary completion
- 1 Apr 2027 (estimated)
- Study completion
- 1 Apr 2027 (estimated)
- First posted
- 13 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
One of the most prominent indicators of prenatal androgen exposure is considered to be the ratio of second and fourth finger lengths (2D:4D). The 2D:4D finger ratio refers to the ratio of the length of the second finger (2D; index finger) and the fourth finger (4D; ring finger). Evidence suggests that 2D:4D is developmentally stable and stabilizes from the second trimester of pregnancy. It has been reported that the 2D:4D ratio correlates positively with estrogen and negatively with testosterone. In both sexes, prenatal testosterone levels are inversely related by a 2D:4D ratio, which does not change with age. Androgens can have direct trophic effects on target cells or indirectly affect neuronal growth through neurotrophic mediators released locally by steroid-sensitive neuronal or glial cells. Prenatal testosterone can have long-term organizational effects on the structure and function of various body systems (e.g., cardiovascular and musculoskeletal systems) that are important for physical activity and exercise.
Detailed description
One of the most prominent indicators of prenatal androgen exposure is considered to be the ratio of second and fourth finger lengths (2D:4D). The 2D:4D finger ratio refers to the ratio of the length of the second finger (2D; index finger) and the fourth finger (4D; ring finger). Evidence suggests that 2D:4D is developmentally stable and stabilizes from the second trimester of pregnancy. It has been reported that the 2D:4D ratio correlates positively with estrogen and negatively with testosterone. In both sexes, prenatal testosterone levels are inversely related by a 2D:4D ratio, which does not change with age.
From a gender perspective, differences have been found in the basic motor skills of boys and girls. Boys have greater object control skills than girls. Gender is one of the most studied variables in motor development. Many longitudinal studies show that boys perform better in gross motor skills such as running and jumping, while girls are more successful in fine motor tasks such as drawing or manipulating small objects. Sensory processing involves the capacity to receive, interpret, organize, and respond to sensory input from both one's own body and the external environment. Sensory processing disorders can be observed in infants due to the immaturity of their systems. There are very few studies on measuring finger length in the early stages of newborns. To our knowledge, the relationship between intrauterine androgen exposure (2D:4D) and motor development and sensory processing has not yet been investigated. Therefore, the planned study aims to evaluate the 2D:4D finger ratio in 12-18-month-old infants and to examine the relationship between this ratio and motor development and sensory processing.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy infants | – | Behavioral: Digit Ratio, Behavioral: Motor development, Behavioral: Sensory processing functionsHealthy, full-term (37-40 weeks of gestation) infants aged 12 to 18 months and their families will be invited to participate in the study. |
Who may qualify
- Ages
- 12 to 18 months
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
- Study population
- The study will include healthy, full-term (37-40 weeks of gestation) infants aged 12 to 18 months.
Key inclusion criteria (2 listed)
- Term infants (37-40 weeks),
- Infants aged 12-18 months
Key exclusion criteria (7 listed)
- 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,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Digit RatioThe lengths of the second (2D) and fourth (4D) fingers will be measured separately on each hand. Measurements will be taken with the baby's hands placed flat on a surface with palms facing upwards. Finger length will be defined as the distance from the midpoint of the proximal crease at the base of the finger to the distal end of the finger. A digital caliper with a precision of 0.01 mm will be used, and two separate measurements will be taken for each finger, with the average value recorded. Based on these measurements, the 2D:4D finger ratio for each hand will be calculated by dividing the length of the second finger by the length of the fourth finger. | Behavioural | Healthy infants |
| Motor developmentThe Peabody Developmental Motor Scale-2 (PDMS-2) is planned to be used to assess motor development. The PDMS-2 test is designed to identify developmental delays in children aged 0-72 months. It is used to evaluate children's motor development with separate tests and rating scales for both gross and fine motor skills. | Behavioural | Healthy infants |
| Sensory processing functionsThe Test of Sensory Functions in Infants was planned for use to assess babies' sensory development. The TSFI is frequently used to evaluate the sensory processing functions of infants aged 4-18 months. It is used to determine whether and to what extent a baby has a sensory processing problem. It consists of 24 items. The TSFI requires the baby to be stimulated and interact with various materials. The total score ranges from 0-49, and the test has normative values for different age groups. Although it can be used from the fourth month onwards, the most reliable and valid results are obtained between 7-18 months. | Behavioural | Healthy infants |
Primary outcome
Sensory processing
Time frame: 12-18 months
The Test of Sensory Functions in Infants is a standardized assessment tool designed to evaluate sensory processing abilities in infants aged 4 to 18 months. The TSFI examines responses across multiple sensory domains, including tactile, vestibular, visual, and oral-motor functions, providing a comprehensive profile of an infant's sensory processing. In the tactile deep pressure response section, it is scored as 0: reverse response, 1: mild defensive response, and 2: integrated response. In the adaptive motor response section, it is scored as 0: no response, 1: disorganized, 2: partial, 3: organized. In the visual-tactile integration section, it is scored as 0: hyperactive, 1: hyporeactive, and 2: normal. The oculomotor test section is scored as 0: no response or poorly integrated, 1: well integrated. Response to vestibular stimulation is scored as 0: adverse response, 1: mild defensive response, and 2: integrated response. The total score ranges from 0 to 49.
Motor development
Time frame: 12-18 months
The Peabody Developmental Motor Scales, Second Edition, is a standardized tool used to assess gross and fine motor skills in children from birth to 5 years of age. The assessment comprises six subtests: reflexes, stationary, locomotion, object manipulation, grasping, and visual-motor integration, which together provide a comprehensive evaluation of a child's motor development. It has been widely validated in both typically developing children and those with various developmental disorders, making it a reliable and widely used instrument in pediatric motor assessment. Items are scored with 0, 1, and 2 points. When the child performs the item according to the specified item criteria, 2 points are given. One point is awarded when the behavior occurs, but the criteria for successful performance are not fully met. A score of 0 is given when the child is unable to try the item or does not reveal any skills when he tries it. Results are expressed as raw, standard, or total motor scores.
Digit Ratio
Time frame: 12-18 months
The lengths of the second (2D) and fourth (4D) fingers of the participants will be measured separately on each hand. Measurements will be taken with the participants' hands placed flat on a surface with the palms facing upwards. Measurements will be performed using a digital caliper with a precision of 0.01 mm, 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 on both hands. To increase the reliability of the measurements, the assessments will be performed twice by a researcher who is blind to motor development and sensory processing skills.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2026.
- Background: PubMed 34751980Cay M, Gurel S. The relationship between mothers' second and fourth finger lengths (2D:4D) and anthropometric measurements (height, weight, head circumference, and 2D:4D) of the newborns. Am J Hum Biol. 2022 May;34(5):e23700. doi: 10.1002/ajhb.23700. Epub 2021 Nov 9.
- Background: PubMed 38956189Ernsten L, Korner LM, Heil M, Schaal NK. The association between 2D:4D digit ratio and sex-typed play in children with and without siblings. Sci Rep. 2024 Jul 2;14(1):15231. doi: 10.1038/s41598-024-65739-1.
- Background: PubMed 31512755Paukner A. Digit ratio (2D:4D) and its behavioral correlates in infant rhesus macaques (Macaca mulatta). Dev Psychobiol. 2020 Nov;62(7):992-998. doi: 10.1002/dev.21917. Epub 2019 Sep 12.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Rabia Zorlular contact
Rabia ZORLULAR principal investigator
Nigde Omer Halisdemir University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Infant Developmental Assessment, run by Nigde Omer Halisdemir University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rabia ZORLULAR (+5424362082, rabiaeraslan118@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sensory processing (time frame: 12-18 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07525726, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.