Gestational age at birth and academic performance: population-based cohort study

Area of Science:

• Perinatal epidemiology
• Developmental neuroscience
• Educational psychology

Background:

• Pre-term birth is a known risk factor for cognitive deficits.
• Limited research exists on cognitive outcomes after post-term birth.
• The impact of weight variations within term and post-term births on cognition is understudied.

Purpose of the Study:

• To examine the association between gestational age (GA) and school performance.
• To investigate the influence of birth weight for GA on these associations.
• To focus on extremely pre-term and post-term births and their impact on academic achievement.

Main Methods:

• A large-scale Swedish population-based record linkage study of children born between 1973-1994.
• Inclusion of a nested sibling comparison design for enhanced causal inference.
• Utilized restricted cubic regression splines to analyze GA and secondary education grades.

Main Results:

• Both pre-term and post-term births were associated with lower average school grades compared to full-term births.
• Children born extremely pre-term (24 weeks) showed a significant grade reduction of 0.43 standard deviations.
• Extremely post-term births (45 weeks) showed a smaller grade reduction of -0.15 standard deviations.

Conclusions:

• Gestational age and birth weight for gestational age independently influence school performance.
• Sibling analyses, while attenuating the effect, supported a causal link between extreme pre-term/post-term birth and academic outcomes.
• Findings highlight the importance of fetal maturation and growth for long-term cognitive development.