by Justin Jackson, Medical Xpress

Credit: Unsplash/CC0 Public Domain

Karolinska Institutet researchers report that children born before 34 weeks of gestation show persistent deficits in cognitive abilities at ages 9 to 10. Impairments appear independent of socioeconomic status, genetic predisposition, and prenatal or child-specific risk factors. Lower scores were observed in vocabulary, working memory, episodic memory, and recall tasks. Children born late preterm (34–36 weeks) or early term (37–38 weeks) performed comparably to those born full term.

Preterm birth affects approximately 13 million infants worldwide each year and remains a leading cause of childhood morbidity and mortality. Although advances in perinatal care have increased survival, cognitive deficits in these children continue to present major public health concerns.

Critical brain development processes that occur between 24 and 40 weeks of gestation may be disrupted by premature birth. Prior research has mostly focused on extremely or very preterm infants, often overlooking those born moderately or late preterm, who constitute a large portion of preterm births.

Cognitive functioning in preterm children tends to lag behind full-term peers, yet most research has measured only overall IQ, not specific cognitive domains. Existing studies have also lacked comprehensive analysis accounting for both genetic and environmental risks.

In the study, "Gestational Age and Cognitive Development in Childhood, " published in JAMA Network Open, researchers conducted a prospective, multicenter, longitudinal cross-sectional study to investigate whether preterm and early-term births are associated with lower cognitive scores in children aged 9 to 10 years compared with full-term peers, adjusting for genetics, prenatal risks, and child-specific factors.

A cohort of 5, 946 children, aged 9 to 10 years, was recruited from the Adolescent Brain and Cognitive Development Study, conducted across 21 data collection sites in the United States.

Participants underwent a series of cognitive assessments including the National Institutes of Health Toolbox, Little Man Task, and Rey Auditory Verbal Learning Test. Researchers computed polygenic scores for cognitive performance using genome-wide association data and adjusted for a range of maternal, child-specific, and socioeconomic variables.

Moderately preterm children (32–33 weeks gestation) had lower composite cognitive scores compared to full-term children. These children also performed worse in vocabulary, working memory, episodic memory, and both short and long-delay recall, with all results showing measurable deficits in vocabulary and memory comparable to missing several months of typical learning progress at that age.

Children born before 32 weeks showed similar deficits while children born at 34 weeks or later had cognitive outcomes indistinguishable from their full-term peers.

The study authors conclude that cognitive impairments linked to moderately preterm birth persist into late childhood and are not explained by socioeconomic status, genetic background, or other known risk factors. Findings indicate that children born before 34 weeks may require continued monitoring and support to address developmental challenges that extend into school-age years.

Early screening and intervention are described as potentially beneficial in improving long-term cognitive outcomes. Cognitive deficits at this age are often associated with lower academic achievement and reduced quality of life, reinforcing the need for targeted resources for children born preterm.

More information: Samson Nivins et al, Gestational Age and Cognitive Development in Childhood, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.4580  Journal information: JAMA Network Open

© 2025 Science X Network