Summary: A large European analysis finds no evidence that having a sibling born preterm increases behavioral problems in children born at term. Researchers examined harmonised data from over 65,000 children and detected no meaningful differences in internalising or externalising behaviour between term-born children with preterm siblings and those whose siblings were all born at term.
Instead, the study identified higher levels of both internalising (for example, anxiety and withdrawal) and externalising behaviours (for example, aggression and impulsivity) among children without siblings. These results challenge assumptions that a sibling’s preterm birth necessarily affects term-born children’s behaviour, and they point to the importance of further research on family structure and child mental health.
Key facts:
- No increased behavioural risk: Term-born children with a younger sibling born preterm did not show greater behavioural difficulties than those with only term-born siblings.
- Only children had higher scores: Children without siblings scored higher on measures of both internalising and externalising behaviour.
- Large, secure data analysis: The study used the DataSHIELD platform to analyse harmonised data for 65,711 children from cohorts in Denmark, Norway, Italy and the Netherlands.
Source: University of Oulu
Background and aim: Published in PLOS Mental Health, this multicohort investigation set out to determine whether term-born children up to 14 years old who have a younger sibling born preterm (before 37 weeks’ gestation) show higher levels of emotional or behavioural problems than term-born children whose siblings were born at term. The researchers also compared these groups with only children to better understand how sibling status relates to behaviour.
The analysis included 65,711 term-born children (49% girls) pooled from four European birth cohorts. Participants were placed into three categories: a risk group with at least one younger preterm-born sibling (n = 427), a reference group with only term-born siblings (n = 12,371), and an only-child group with no siblings (n = 52,913).
Behaviour was measured using parent-reported instruments commonly used in child mental health research: the Strengths and Difficulties Questionnaire (SDQ) and the Child Behaviour Checklist (CBCL). The researchers examined two broad domains: internalising behaviours (including anxiety, depression and social withdrawal) and externalising behaviours (including impulsivity, aggression and rule-breaking).
Analyses were stratified by age (0–4 years, 5–10 years and 11–14 years) and performed using DataSHIELD, a secure analysis platform that enables remote, privacy-preserving access to harmonised data across cohorts. A two-stage individual participant data meta-analysis was carried out to synthesise results across the contributing studies.
Across all age groups, the researchers found no statistically meaningful differences in either internalising or externalising behaviour scores between term-born children who had a younger sibling born preterm and those with only term-born siblings. This suggests that, in this large sample, a sibling’s preterm birth was not associated with detectable changes in the behavioural outcomes measured.
By contrast, only children showed consistently higher mean scores for both internalising and externalising behaviour when compared with the reference group of children who had only term-born siblings. The magnitude of these differences was small but consistent across some age groups, indicating that being an only child may be associated with modestly elevated behavioural scores in this dataset.
Interpretation and implications: The absence of observable behavioural risk among siblings of preterm-born children runs counter to the hypothesis that family stressors associated with preterm birth would necessarily produce increased emotional or behavioural problems in siblings. Nonetheless, the authors caution that siblings of preterm infants remain an understudied population, and that further investigation is warranted—especially longitudinal work that can follow children over time and studies with larger samples of specific subgroups.
Future research should also consider additional dimensions of family life, such as parental stress, resource allocation, and sibling caregiving roles, which may influence child adjustment but were not the primary focus of this analysis. A clearer understanding of these dynamics could inform targeted support or interventions if particular vulnerabilities are identified in subgroups of siblings.
Methodological note: All analyses were conducted using DataSHIELD to protect participant privacy while enabling collaborative, harmonised analyses across multiple cohorts. The project was part of the EU-funded LifeCycle initiative and involved collaboration with related research efforts within the European Human Exposome Network.
About this neurodevelopment and behaviour research news
Author: Meri Rova ([email protected])
Source: University of Oulu
Contact: Meri Rova – University of Oulu
Image: Image credited to Neuroscience News
Original research (open access): “Internalising and externalising behaviour in siblings of children born preterm” by Wnurinham Silva et al., PLOS Mental Health. DOI: 10.1371/journal.pmen.0000334
Abstract (concise overview)
This study examined whether term-born children up to age 14 who have younger siblings born preterm show increased internalising or externalising behavioural problems compared with term-born children with only term-born siblings, and with only children. Using harmonised data from four European birth cohorts, 65,711 term-born children were categorised into a risk group (younger preterm sibling), a reference group (only term-born siblings) and an only-child group. Parent-reported SDQ and CBCL scores were converted to z-standardised scores and compared across groups and age strata. A two-stage individual participant data meta-analysis found no evidence that having a younger sibling born preterm was associated with higher internalising or externalising scores. Only children, however, had higher scores than the reference group on both behavioural domains. The findings suggest sibling preterm birth is not, by itself, a detectable risk factor for elevated behavioural problems in term-born children in this large sample, though continued research is recommended to explore potential subgroup vulnerabilities and the broader family context.