About the study

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

The main aim of the project was 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 was managed by the UCL Centre for Longitudinal Studies, with support from a consortium of partners.
• Ipsos carried out the data collection for the study.
• It was 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 outcomes

Survey component

The Early Life Cohort Feasibility Study draws a nationally representative sample of babies born in a two-month period from all four UK nations. In England, Wales and Scotland the babies were born in November and December 2022, and in Northern Ireland the babies were born in June and July 2023. Interviews took place when the babies were around 9-12 months old.

In England, Wales and Scotland, families were first contacted in July 2023 and fieldwork finished by the end of June 2024. In Northern Ireland, families were first contacted in February 2024 and fieldwork finished in September 2024.

In total, 1,918 families took part:

• 1,005 families in England
• 273 in Wales
• 319 in Scotland
• and 321 in Northern Ireland.

1,850 mums and 1,256 dads took part.

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

Read the briefing paper to learn more about the findings from the survey component (April 2025, PDF).

Small-scale field tests

The small-scale field tests, also referred to as ELC+, assessed the feasibility of collecting novel child development, home environment and stress markers in the home by agency fieldworkers.

The measures tested included neuroscience-informed and anthropometric measures (EEG, eye tracking, adiposity), hair samples, and audio-recording of the home language environment.

Eight agency interviewers were trained and conducted these assessments with 93 children aged 6-12 months from London and Cambridge in a 100-minute home visit. ELC+ concluded that a battery of this kind would be feasible and would produce high-quality novel data. Feedback from parents was also consistently very positive.

Read the briefing paper to learn more about the findings from the small-scale field tests (April 2025, PDF).

Study content

Data collection

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

The feasibility of innovative measures to capture babies’ development was also tested. These comprised 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 also tested 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 was assessed via small scale field tests, separate to the main data collection.

The study design will 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.

Questionnaires

Parents were asked about their baby’s health and growth, behaviour and development, sleep, diet and activities they do with their child. They were 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 were invited to interview, including those who live apart from their child’s other parent. Each parent was interviewed separately.

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

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

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

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

When no parents took part at an address, an invite was sent for one parent to take part in a 40-minute non-response web survey.

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

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

We have also worked with experts to understand how best to engage babies who are extremely vulnerable, including children born into care. Findings and recommendations from these expert discussions can be read in this Recommendations for next steps report (October 2024, PDF).

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 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.