Early Life Cohort Feasibility Study

The Early Life Cohort Feasibility Study is testing the feasibility of sampling and recruitment for an innovative new UK-wide birth cohort study. The project started in April 2021, and is due to finish in December 2024.

About the study

The Early Life Cohort Feasibility Study is collecting data on a new generation of UK-born babies in their first year of life. It is capturing information about their economic and social environments, and their health, wellbeing and development.

The main aim of the project is to test the feasibility of sampling and recruitment for an innovative new UK-wide birth cohort study. However, the data from the feasibility study itself will also be made available to the research and policy community.

  • The study is managed by the UCL Centre for Longitudinal Studies, with support from a consortium of partners.
  • Ipsos are carrying out the data collection for the study.
  • It is funded by the Economic and Social Research Council.

Study aims

The Early Life Cohort Feasibility Study aims to paint a nationally representative picture of the circumstances and lives of a new cohort of babies born at a critical time in the UK’s history.

With the economic and social repercussions of the COVID-19 pandemic, and the impacts of Brexit on our economy and society still unknown, the need to understand the challenges facing this generation of babies, their development as children and their future prospects is pressing.

The primary scientific aim of the study is to understand how inequalities in early child development are changing over time, and to learn whether the social and biological factors driving these trajectories are evolving.

The key scientific themes include:

  • cognitive, social, and emotional development of infants
  • infant-parent relationships, and the early home environment
  • infant health, including growth, nutrition and sleep
  • mental health of parents and the developing child
  • social, environmental and neighbourhood influences on infant and family
  • inequality, disadvantage, and social mobility
  • genomics, early adversity and biological embedding of stress.

Study design and content

The Early Life Cohort Feasibility Study draws a nationally representative sample of babies born in a two-month period from all four UK nations. It aims to recruit over 1,800 families with at least 900 in England and 300 each in Wales, Scotland and Northern Ireland.

In England, Wales and Scotland, families were first contacted in July 2023 and fieldwork will finish in May 2024. In Northern Ireland, families were first contacted in February 2024 and fieldwork will finish in August 2024.

Interviews will take place when the babies are around 8-10 months old.

The data will be available from the UK Data Service in 2025.

Data collection

Data collection involves interviews with mothers and fathers. Saliva samples from parents and infants for DNA extraction are collected from an experimental sub-group to test the impact on participation.

The feasibility of innovative measures to capture babies’ development is also being tested. These comprise neuro scientific measures (looking-time task, eye tracking, mobile EEG to measure brain activity, together with use of an actimetry device), and measurement of the early language environment (through placement in the home of a LENA recording device).

We are also testing additional infant biosamples (hair samples) and infant anthropometry (weight, length, head circumference and adiposity). The feasibility of collecting these specialist objective measurements using trained fieldwork agency staff is being assessed via small scale field tests, separate to the main data collection.

The study design will also enable linkage to electronic and other administrative records of babies and parents as well as to geo-environmental data, which can provide information on environmental and other conditions in the places they spend time, including homes, childcare locations, and hospitals.


Parents are asked about their baby’s health and growth, behaviour and development, sleep, diet and activities they do with their child. They are also asked about their home and family, including other children and their partner/other parent, their work situation and family finances, health and wellbeing, parenting approach and relationship with their baby, relationship support and services received, and childcare arrangements.

Both mothers and fathers are invited to interview, including those who live apart from their child’s other parent. Each parent is interviewed separately.

One parent is asked to complete a 60-minute interview in person with an interviewer. This longer interview is usually done by the parent who spends the most time with the baby. In most families, this is the child’s mother. There are options to complete the interview by telephone and by video call if an in-person interview is not possible.

The other parent living with the baby, usually the child’s father, is asked to complete a 30-minute interview, either in-person with an interviewer or online. This interview is shorter because some questions only need to be asked once per baby or per household.

Parents who live apart from their baby, usually the fathers, are asked to complete a separate 40-minute interview. This interview can also be completed by telephone or by video call.

Resident partners of parents, including those who live apart from the baby, are also invited to be interviewed.

Download the Early Life Cohort Study final questionnaire (February 2024, PDF)

Representativeness and inclusion

The study design focuses on maximising participation of traditionally ‘less often heard’ populations.

In England, there are sample boosts for babies born into disadvantaged and ethnic minority families (Black Caribbean, Black African, Pakistani and Bangladeshi). There are further boosts of births in Scotland, Wales and Northern Ireland. We will use experiments to test the effectiveness of different levels of incentives for taking part.

We are engaging fathers into the study, including those living in their own households.

We are also working with experts to understand how best to engage babies who are extremely vulnerable, including children born into care.

Public engagement

The project team has undertaken careful public engagement with parents of children and young people to ensure acceptability of the proposed sampling, data collection and record linkage approaches. The public engagement was designed to enable individuals’ voices to be heard and acted upon in the design of the study, and to help ensure the study serves the needs of the people it represents.

In addition, the project team has carried out extensive public engagement and consultation with policy and practitioner networks and with academic data users to determine evidence needs and scientific priorities for the feasibility study.

Further information and reports can be found on our Public engagement page.

Key features of the study

Approach to sampling

Securing access to a high-quality sampling frame of babies born in all four UK countries is central to the feasibility study aims.

We worked with agencies across the UK to develop applications to access centrally held records for this purpose, under appropriate governance mechanisms. Alongside this, we developed a programme of public engagement work to ensure public acceptability of our plans for sampling.

Our preferred approach to use birth registrations, linked to NHS maternity records, has been successfully implemented in England, Wales and Scotland. In Northern Ireland, maternity records are used as the sampling frame.

Birth registrations provide universal coverage of the population of babies, contain key characteristics of the baby, mother and father, including where they live, and may allow fathers resident at a different address to the baby to be recruited in their own right.

NHS maternity records contain additional information which could be used for sampling, including the ethnic group of the baby, and facilitates timely access to updated addresses for any post-birth moves.

Our approach was necessarily flexible and pragmatic in each UK nation, taking into account public views, as well as local processes and systems, logistics and governance around the implementation of an opt-out model of consent and timeliness.

Different approval processes, data sources and sample provision in each UK nation has meant that the study started later in Northern Ireland than in England, Wales and Scotland.

Public engagement

The study is designed for the public benefit, and our core values include a commitment to trustworthiness and transparency in the use of personal data, and enabling  individuals’ voices to be heard and acted upon.

We have worked with families with children to co-design the study in way that allows participant voices from a diverse set of backgrounds to be heard.

This included conducting qualitative research with parents who live apart from their children and parents from low-income families and minority ethnic families.

The National Children’s Bureau and First 1001 Days Movement have supported a policy and practitioner consultation. We also consulted widely with data users from the academic, policy and third sectors.

Find out more on the Public engagement page.

Biosamples and biomeasures

An important aim of the study is to assess the feasibility of collecting biosamples and bio-measures.

This includes saliva samples from both the infant and their parents for DNA extraction, in an experimental sub-group of the main survey.

These measures will enable researchers to understand the interplay between biology and social environment on the developing child, including testing hypotheses relating to biological embedding of social adversity, mechanisms underlying resilience, and gene-environment interactions. The opportunity to fully genotype the cohort and natural parents before subsequent attrition takes place also brings strong methodological benefits.

We randomised the DNA sample collection to a stratified sub-sample (about 600 issued sub-sample) to test whether this significantly impacts on successful recruitment into the study. Further, we will test levels and patterns of consent to provide DNA samples among those who do take part. The feasibility study also tests logistical factors in undertaking these collections at scale. It will also allow us to test sample storage and analysis options for the main study.

Novel forms of data collection

We are testing the feasibility of a number of novel approaches to data collection in the core domains of cognition, emotion, language, social development and the home and wider environment via small-scale field tests separate to the main survey.

This includes capture of neuro-cognitive function using direct assessment of neurocognitive development using habituation and looking-time-based methodologies. This will also be supplemented with state of the art techniques such as eye-tracking and mobile EEG.

We also explore the potential for using wearable and other devices to allow the passive collection of real-time behaviour through direct measurement. This includes measuring the child’s linguistic environment (LENA system), activity level and physiology using wearable sensors.

These small-scale field tests focus exclusively on the practical and training requirements for using these complex measurements in the context of a national cohort stud. They also focus on the extent to which fieldworkers can be trained to successfully collect high-quality measurements in the home context.

Record linkage

Administrative and geo-environmental linkages are embedded in the feasibility study from the outset.

Going back in time, these will cover histories of the parents from before the pregnancy, plus pregnancy and birth records. Going forwards, records will be linked from a constellation of agencies encountered by the baby and family, as the baby progresses through infancy and childhood.

We are testing models of consent and will initiate applications to link to centrally held birth registration and NHS health records (for baby and mother). These would include:

  • maternal health records
  • primary care
  • inpatient admissions
  • outpatient appointments
  • A&E attendances
  • critical care
  • child records (neonatal records, newborn screening, child measurement, health and development data, congenital anomaly and rare diseases)
  • vital events records including deaths
  • prescribing and vaccination data.

We also include consent for linkage to parental and child education records, and to social care records.


Alissa Goodman Professor of Economics, Director of CLS and Co-Director of the Early Life Cohort Feasibility Study

Phone: 020 7612 6231
Email: alissa.goodman@ucl.ac.uk

Alissa Goodman is Professor of Economics, Director of the Centre for Longitudinal Studies, and Co-Director of the Early Life Cohort Feasibility Study, a project funded by ESRC to test the feasibility of a new birth cohort for the UK. She is a Co-Investigator on two further new national cohort projects, Children of the 2020s and the COVID Social Mobility & Opportunities Study. Alissa joined CLS in 2013 as PI of the 1958 National Child Development Study, having previously worked at the Institute for Fiscal Studies, where she served as its Deputy Director (2006-2012), and Director of its Education and Skills research sector.

Alissa’s main research interests relate to inequality, poverty, education policy, and the intergenerational transmission of health and wellbeing. Alissa was awarded a CBE for services to social science in 2021.

Lisa Calderwood Managing Director of CLS and Co-Director of the Early Life Cohort Feasibility Study

Phone: 020 7911 5510
Email: l.calderwood@ucl.ac.uk

Lisa is a Professor of Survey Research. She has over 20 years’ experience of the design and implementation of complex, large scale longitudinal surveys.

Her research areas include non-response, innovations in participant engagement, new technologies and mixed-modes of data collection, administrative data linkage and integrating bio-measures in social surveys. Lisa has strong national and international networks within the cohort studies community, is a co-ordinator for the cohort network of Society of Lifecourse and Longitudinal Studies and is involved in the European-wide COORDINATE and GUIDE initiatives.

Pasco Fearon UCL Chair in Developmental Psychopathology and Co-Director of the Early Life Cohort Feasibility Study

Phone: +44 (0) 20 7679 1244
Email: p.fearon@ucl.ac.uk

Professor Pasco Fearon is a leading expert in early child development, specialising in early parenting, attachment, parental mental health and the development of children’s emotional and behavioural problems.

Pasco is a Clinical Psychologist and Professor at the University of Cambridge and UCL. He is Director of the Centre for Family Research at the University of Cambridge and the Developmental Neuroscience Unit at the Anna Freud National Centre for Children and Families (AFNCCF). He has extensive expertise in longitudinal research in the infancy and early childhood period, and in the measurement of the home environment and children’s cognitive and emotional development.

Project team

Scientific Leadership and Delivery Team

Karen Dennison (UCL Centre for Longitudinal Studies)

Dr Pia Hardelid (UCL)

Dr Lucy Griffiths (University of Swansea)

Professor Rebecca Reynolds (University of Edinburgh)

Dr Orla McBride (Ulster University)

Professor Kerina Jones (University of Swansea)

Rebecca Goldman (Fatherhood Institute)

Adrienne Burgess (Fatherhood Institute)

Professor George Ploubidis (UCL Centre for Longitudinal Studies)

Professor Emily Jones (Birkbeck)

Professor Mark Johnson (University of Cambridge)

Dr Bonamy Oliver (UCL)

Study team

Dr Susan Purdon (Bryson Purdon Social Research)

Dr Rachael Wood (Public Health Scotland and University of Edinburgh)

Professor Chris Dibben (University of Edinburgh)

Professor Dermot O’Reilly (Queen’s University Belfast)

Professor Gary Pollock (Manchester Metropolitan University)

Paul Bradshaw (ScotCen)

Professor Heather Joshi (UCL Centre for Longitudinal Studies)

Dr Erica Wong (UCL Centre for Longitudinal Studies)

Dr Alyce Raybould (UCL Centre for Longitudinal Studies)

Dr Louise Gosse (Birkbeck)

Project partners

Nuffield Family Justice Observatory

29 April 2021

The Nuffield Family Justice Observatory supports better outcomes for children by improving the use of data and research evidence in the family justice system in England and Wales. They will host a workshop of academics and practitioners to explore what it would take to establish a national longitudinal birth cohort study of children in need.

First 1001 Days Movement

29 April 2021

The First 1001 Days Movement is an alliance of charities, parliamentarians, academics, and practitioners with an interest in babies’ emotional wellbeing, coordinated by the Parent-Infant Foundation. They will support our consultation with the policy and practice community.

National Children's Bureau

29 April 2021

The National Children’s Bureau (NCB) has worked for the last 50 years to address inequalities which prevent children and young people from achieving their full potential. NCB will coordinate engagement with parent and young person advisory groups and the policy and practice community, and will promote early findings.

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL

Email: clsdata@ucl.ac.uk

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