Preterm Birth Before 34 Weeks Linked to Lasting Cognitive Challenges in Children: JAMA
Sweden: In a significant new study examining child development, researchers have found that children born moderately preterm- specifically before 34 weeks of gestation-may be at a greater risk for long-term cognitive difficulties, regardless of their socioeconomic status (SES), genetic makeup, or other known risk factors.
"The findings highlight the importance of ongoing monitoring for all preterm children, especially those born before 34 weeks of gestational age, as they may experience more significant developmental challenges as they grow," the researchers wrote in JAMA Network Open.
Preterm and early-term births are established risk factors for cognitive impairment, yet there is a lack of comprehensive studies that consider genetics, prenatal risks, and child-specific factors in high-risk populations. To fill this knowledge gap, Samson Nivins, Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden, and colleagues aimed to explore the long-term cognitive outcomes of children born at various gestational ages, ranging from very preterm (28-31 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), and early term (37-38 weeks), compared to full-term births (≥39 weeks). The research also accounts for genetics and other relevant risk factors, offering a deeper understanding of how these variables influence cognitive development over time.
For this purpose, the researchers conducted a prospective, multicenter study involving children aged 9 to 10 years recruited from the Adolescent Brain and Cognitive Development Study. Cognitive assessments were performed using various tests, and polygenic scores for cognitive performance (cogPGS) were generated.
The study examined the impact of preterm and early-term birth on cognitive outcomes, with full-term birth as the reference. Regression models analyzed the relationship between gestational age and cognitive scores, adjusting for factors such as socioeconomic status, cogPGS, prenatal risks, and child-specific variables. Data analysis was completed between March and June 2024.
Key Findings:
- The study included 5946 children with an average age of 9.9 years, 51.8% being male. Among them, 0.9% were very preterm, 1.8% moderately preterm, 7.6% late preterm, 4.4% early term, and 85.2% full term.
- The cognitive performance score (cogPGS) showed a positive relationship with the overall cognitive score.
- Children born moderately preterm had lower cognitive scores than full-term children, particularly in vocabulary, working memory, episodic memory, and recall.
- Children born at 32 weeks or earlier had the lowest cognitive scores .
- Late-preterm and early-term children showed similar cognitive outcomes to those born full-term.
- These findings were independent of socioeconomic status, cogPGS, and other risk factors.
These findings indicate that moderately preterm birth is linked to long-term cognitive challenges, particularly in areas like language, working memory, and episodic memory, independent of genetics and other risk factors.
"Preterm birth, especially before 34 weeks, may have lasting effects on cognition, suggesting that biological risks can impact development over time. In contrast, children born late preterm or early term did not show similar cognitive issues," the authors noted. They concluded, "These results underscore the need for continued follow-up of preterm children, particularly those born before 34 weeks, as they may face greater developmental challenges as they grow."
Reference:
Nivins S, Padilla N, Kvanta H, Ådén U. Gestational Age and Cognitive Development in Childhood. JAMA Netw Open. 2025;8(4):e254580. doi:10.1001/jamanetworkopen.2025.4580
