ISRCTN ISRCTN66894783
DOI https://doi.org/10.1186/ISRCTN66894783
Secondary identifying numbers CCMO NL62692.058.17
Submission date
29/06/2021
Registration date
22/07/2021
Last edited
12/10/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Other
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
The aim of this study is to test whether the use of either a soft baby carrier or an infant seat 2 months after the birth of their first baby is associated with more sensitive and involved fathering, different hormonal levels, and different brain responses to infant signals.

Who can participate?
Men who recently had their first baby

What does the study involve?
Participants are randomly allocated to receive either a soft baby carrier or an infant seat, to be used 6 hours per week for 3 weeks. The quality of their interaction with their infant is measured using scales at the start of the study, after the intervention (3.5 months) and at follow-up (7 months). Involvement in infant care is measured using a questionnaire and a mobile phone application, hormone levels are measured using saliva and hair samples, and brain activity is measured using MRI scans at the same timepoints.

What are the possible benefits and risks of participating?
Participants can enjoy interacting with their infant in the infant seat, or carrying their baby around in the soft baby carrier. No risks are known.

Where is the study run from?
Vrije Universiteit Amsterdam and Leiden University (Netherlands)

When is the study starting and how long is it expected to run for?
October 2014 to September 2020

Who is funding the study?
European Research Council (Belgium)

Who is the main contact?
Marian Bakermans-Kranenburg, PhD
m.j.bakermans@vu.nl

Study website

Contact information

Prof Marian Bakermans-Kranenburg
Scientific

Paulus Buysstraat 13
Leiden
2334 CH
Netherlands

ORCiD logoORCID ID 0000-0001-7763-0711
Phone +31 (0)642565426
Email m.j.bakermans@vu.nl

Study information

Study designInterventional randomized controlled trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Home
Study typeQuality of life
Participant information sheet Not available in web format, please use contact details to request a participant information sheet
Scientific titleEffects of a soft baby carrier on fathers' hormonal levels, neural processing of infant signals, and parenting behaviour
Study objectives1. An intervention with a baby carrier (versus an infant seat) for fathers in the early postnatal phase results in different hormonal, neural and behavioral responses to infant stimuli
2. The baby carrier intervention promotes fathers’ parenting in terms of quantity (involvement) and quality (sensitivity)
3. The baby carrier intervention affects fathers’ basal hormonal levels that may mediate neural and behavioral effects
Ethics approval(s)Approved 21/02/2018, Ethics Committee of the Leiden University Medical Centre on behalf of the Central Committee on Research Involving Human Subjects (CCMO) (Albinusdreef 2, 2300 RC Leiden, Netherlands; +31 (0)715263241; cme@lumc.nl), ref: P17.215, NL 62692.058.17
Health condition(s) or problem(s) studiedSensitive and involved parenting in fathers
InterventionParticipants are randomised using a random number generator, odd vs even numbers decided on assignment.

This intervention manipulates the amount of physical contact between father and child. Fathers in the intervention group (half of the sample, randomly selected) will receive an ergonomic soft baby carrier. Infants in the carrier are chest to chest with their father, supported by the adult's upper torso. Fathers are requested to use the baby carrier for at least 6 hours per week, spread over a minimum of 4 days, for 3 weeks. Fidelity will be measured using a motion logger and a temperature data logger fixed to the baby carrier.

In parallel with the intervention sessions, the fathers in the control group are invited to have their baby close by in a baby seat, a Doomoo seat (Doomoo, 2004), inducing proximity between the father and baby without physical contact. Fathers are requested to use the baby seat for at least 6 hours per week, spread over a minimum of 4 days, for 3 weeks. Fathers receiving the control intervention who use a baby carrier will not be discouraged from doing so. The researchers will use intent-to-treat analyses, keeping them in the control group.
Intervention typeDevice
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)Kodaki Flip or Ergobaby Adapt infant carrier, Doomoo infant seat
Primary outcome measureQuality of interaction with infant measured using the Ainsworth (1974) observation scales and Challenging Play Behavior scales at baseline (2 months), after the intervention (3.5 months) and at follow-up (7 months)
Secondary outcome measures1. Involvement in infant care measured using a questionnaire and a mobile phone application at baseline (2 months), after the intervention (3.5 months) and at follow-up (7 months)
2. Oxytocin levels and cortisol levels (baseline and reactivity to interaction with infant) measured using saliva and hair samples at baseline (2 months), after the intervention (3.5 months) and at follow-up (7 months)
3. Differential activity and connectivity in parental brain areas, resting state and reactivity to infant stimuli, measured using (f)MRI at baseline (2 months), after the intervention (3.5 months) and at follow-up (7 months)
Overall study start date17/10/2014
Completion date01/09/2020

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
SexMale
Target number of participants140
Total final enrolment80
Key inclusion criteria1. Male adults who recently had their first baby
2. The infant is healthy and full-term (i.e., born after 37 weeks of gestation)
Key exclusion criteria1. Not cohabitating with the biological mother of the child
2. No mastery of the Dutch language
3. A current endocrine disorder, or the use of medication potentially interfering with the endocrine system
4. A cardiovascular disease
5. A psychiatric disorder
6. Current heavy drinking, regular use of soft drugs, use of hard drugs within the past 3 months
7. MRI contraindications (e.g., metallic foreign objects, a neurological disorder)
8. Using a baby carrier for over 5 hours per week at the time of inclusion
9. Having an upper torso injury that could hinder the use of a baby carrier
Date of first enrolment02/03/2018
Date of final enrolment21/02/2020

Locations

Countries of recruitment

  • Netherlands

Study participating centres

Vrije Universiteit Amsterdam
Van der Boechorststraat 7
Amsterdam
1085BT
Netherlands
Leiden University
Wassenaarseweg 5
Leiden
2300RB
Netherlands

Sponsor information

European Research Council
Research council

Covent Garden
Place Charles Rogier 16
1210 Saint-Josse-ten-Noode
Brussels
BE-1049
Belgium

Phone +32 (0)12345678
Email Anton.TOPALOV@ec.europa.eu
Website https://erc.europa.eu
ROR logo "ROR" https://ror.org/0472cxd90

Funders

Funder type

Research council

H2020 European Research Council
Government organisation / National government
Alternative name(s)
H2020 Excellent Science - European Research Council, European Research Council, H2020 Wissenschaftsexzellenz - Für das Einzelziel 'Europäischer Forschungsrat (ERC)', H2020 Ciencia Excelente - Consejo Europeo de Investigación (CEI), H2020 Excellence Scientifique - Conseil européen de la recherche (CER), H2020 Eccellenza Scientifica - Consiglio europeo della ricerca (CER), H2020 Doskonała Baza Naukowa - Europejska Rada ds. Badań Naukowych (ERBN), EXCELLENT SCIENCE - European Research Council, WISSENSCHAFTSEXZELLENZ - Für das Einzelziel 'Europäischer Forschungsrat, CIENCIA EXCELENTE - Consejo Europeo de Investigación, EXCELLENCE SCIENTIFIQUE - Conseil européen de la recherche, ECCELLENZA SCIENTIFICA - Consiglio europeo della ricerca, DOSKONAŁA BAZA NAUKOWA - Europejska Rada ds. Badań Naukowych, ERC, CEI, CER, ERBN

Results and Publications

Intention to publish date01/11/2021
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination plan1. Protocol (Open Science Framework (OSF) preregistration) at https://osf.io/6q3t5/
2. Planned publication in a high-impact peer-reviewed journal
IPD sharing planThe Principal Investigator should be contacted for access to the datasets: Prof. Dr Marian Bakermans-Kranenburg (m.j.bakermans@vu.nlor, mjbakermans@gmail.com). Pseudonymized data will be shared, and in some cases (dependent on the participants’ specific permission) videotaped parent-infant interaction can be shared. The data will become available 1.5 years after the end of the project, i.e. 1 July 2023; they will be available for a period of 10 years. A data and material license agreement, specifying the aim and type of data sharing, will be signed by both parties. This ensures a legal basis for data sharing and prevents overlap of research projects. Data have been pseudonymized when possible.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Other publications Pretest results 30/06/2021 05/08/2021 Yes No
Results article 01/10/2021 12/10/2021 Yes No

Editorial Notes

12/10/2021: Publication reference added.
05/08/2021: Internal review.
06/07/2021: Trial's existence confirmed by the Ethics Committee of the Leiden University Medical Centre.