2025

Background

Preterm birth, being born before your due date, can be associated with changes to brain development and challenges during childhood and beyond, such as cerebral palsy (movement problems), learning difficulties, vision or hearing problems, and mental health problems. 

Socioeconomic status (SES) refers to an individual's social standing, which is affected by their access to financial, educational, social, and health resources. In babies, SES may be measured at three levels: 

1. Neighbourhood deprivation - how deprived or rich a neighbourhood is. In Scotland, this is captured using the Scottish Index of Multiple Deprivation (SIMD): a postcode-based score that includes neighbourhood-level information about income, employment, health, education, housing, crime, and access to services.
2. Family SES - parental education level and occupation.
3. Subjective SES - a measure of how someone perceives their social standing and quality of life.

Lower, compared to higher, SES is associated with differences in child brain structure and an increased chance of developing learning difficulties and mental health problems.

We previously studied how preterm birth and a family’s socioeconomic status relates to brain structures in the neonatal period, around their due date, and found that they both had effects. White matter is the parts of the brain connecting different brain regions, and we already know it is important for outcomes in babies born preterm. We now wanted to look at how preterm birth and a family’s socioeconomic status related to development of the white matter of the brain across childhood, in the neonatal period and at five years of age. 

Research questions

We looked at how preterm birth and low socioeconomic status relate to white matter in the brain in newborn babies around their due date and at five years. We also looked at whether this relationship is different depending on what we used to describe socioeconomic status.

Findings

In the neonatal period among preterm babies, those who were born closer to term (i.e. with higher gestational age) had more “mature” white matter. Similarly, children whose mothers had higher education also showed more mature white matter. In contrast, the neighbourhood-level measure did not show a strong association at this age. 

At five years old for preterm-born children, the story changes slightly. The link between how early they were born and their white matter structure depended more on neighbourhood-level deprivation (rather than maternal education). 

In other words, both preterm birth and socioeconomic environment matter — but their relative importance changes over time.

Conclusions

Brain development is shaped by more than just biology and medical factors. When babies are born early, they are biologically more vulnerable — but their postnatal environment, including socioeconomic conditions, also plays a role. The influence of social conditions changes over time. Right after birth, family-level factors (like maternal education) seem more important; by early childhood, broader neighbourhood-level factors become more relevant.

We don’t yet know how preterm birth and poverty affect brain structure. However, supporting families and reducing poverty, or the effects of poverty, could improve preterm brain development. Our results suggest we might need to adapt what interventions we give as children grow, supporting families in early life, and focusing on the wider neighbourhood as they grow up.

Background information

Babies born prematurely, before 37 weeks of gestation, may experience difficulties with motor coordination, and social and emotional adjustment. 

Whe studying movement and behaviour in natural environments or in laboratory observations, researchers tend to focus on the average of a movement quality (e.g., kinematic acceleration) or the amount of a type of behaviour. 

There have been advances in computational methods that quantify motor kinematic dynamics, in other words patterns of change from one moment to the next. One such measure is entropy, which measures how complex a signal is. Similar methods have been applied to behavioural data, although these are still relatively novel.

Previous work suggest that entropy is sensitive to context and motor development, and that lower entropy may potentially capture stereotypical movements or generic developmental risks. In this proof-of-concept study, we use computational dynamic measures to investigate movement and behaviour in contexts where infants respond to different levels of social interaction and emotional stress. 

Research questions

Do motor kinematic dynamics and behavioural dynamics differ amongst babies born prematurely and babies born at full-term?

How does context (differing in social interaction and stress levels) affect these motor and behavioural markers?

Findings

Motor kinematic dynamics were sensitive to social interactive and emotional demands in both groups of babies. 

We also found greater left ankle and torso entropy amongst babies born prematurely compared to babies born at full term. This pattern of difference potentially reflects differences in motor development and cerebral lateralisation in babies born prematurely, rather than an indication of stereotypical movements or being at developmental risk.

We did not find differences between groups or between contexts, when analysing the behavioural dynamics.

Conclusions

We found preliminary evidence of differences in movement dynamics between babies born prematurely and babies born at term. Measures of movement dynamics are scalable to real-world data collection and can be useful early markers of developmental health, but our findings still need to be replicated in larger samples and validated. Furthermore, analysis of behavioural dynamics still require methodological development.