Long-Term Cognitive Outcomes in Moderately Preterm Birth

TOPLINE:

Moderately preterm birth independently predicted lower cognitive scores in late childhood.

METHODOLOGY:

• This cross-sectional study analysed how gestational age affects cognition in children aged 9-10 years by using polygenic scores to separate biological from environmental influences.
• The study population included 5946 children (mean age, 9.9 years; 51.8% boys) who were stratified on the basis of their gestational age: Those born very preterm (0.9%), moderately preterm (1.8%), late preterm (7.6%), early term (4.4%), and full term (85.2%).
• Cognitive assessments were conducted using the National Institutes of Health Toolbox (vocabulary, memory, and processing speed), Rey Auditory Verbal Learning Test, and Little Man Task.
• Models were adjusted for socioeconomic status (SES), polygenic scores for cognitive performance (cogPGS), maternal health (diabetes and hypertension), and birth complications, with scanner sites as random effects.
• The primary outcome was the composite cognitive score (β); secondary outcomes included individual cognitive domain scores (vocabulary/memory), with Bonferroni-adjusted P < .005.

TAKEAWAY:

• Compared with children born full term, those born moderately preterm (32-33 weeks) showed significant cognitive deficits: Composite cognitive score (β, −0.39; P < .001), vocabulary (β, −0.36), working memory (β, −0.27), episodic memory (β, −0.32), and short-delay recall (β, −0.36) and long-delay recall (β, −0.29) tasks.
• Children born ≤ 32 weeks had the poorest outcomes (composite cognitive score: β, −0.35; P < .001), with lower scores in vocabulary, working memory, episodic memory, and both short- and long-delay recall and lower visual reaction times (β, −0.19 to −0.33) observed.
• Both cogPGS (β, 0.14; P < .001) and SES (β, 0.26; P < .001) independently predicted better cognitive scores.
• No significant differences in cognitive scores were observed between children born at 34-36 weeks (late preterm) or 37-38 weeks (early term) and those born full term.

IN PRACTICE:

“Our results suggest that children born before 34 weeks’ gestational age are at higher risk for cognitive problems regardless of genetic or environmental factors,” the authors wrote.

SOURCE:

This study was led by Samson Nivins, PhD, Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden. It was published online on April 14, 2025, in JAMA Network Open.

LIMITATIONS:

This study included polygenic scores accounted for less than 15% of cognitive variation, indicating incomplete capture of other genetic factors. Retrospective reporting of maternal and neonatal information could have introduced recall bias. The exclusion of children born extremely preterm, with low birth weight, or with neurologic issues may have introduced selection bias.

DISCLOSURES:

This study was supported by a postdoctoral grant from the Stiftelsen Frimurare Barnhuset, Stockholm. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.