Early-onset neonatal infection and school performance: a Danish nationwide population-based cohort study.

Objectives: We aimed to study the association between early-onset neonatal infection in near-term and term children and school performance based on mandatory tests in reading and mathematics.

Methods: We conducted a nationwide register-based cohort study including all Danish near-term and term singletons born from 1997 to 2009. Early-onset infection was defined as an invasive bacterial infection during the first week of life. Infections were categorized into diagnosed sepsis or meningitis, and culture-positive sepsis or meningitis verified by bacteria cultured from blood or cerebrospinal fluid. Multivariable mixed model linear regression was used to estimate mean differences in test scores, expressed as standard deviation scores (SDSs) with 95% CI.

Results: Among 638 402 children, 2 362 046 test scores were available from 9 to 15 years of age. A total of 5347 children were diagnosed with sepsis and 73 with meningitis, while 135 also had culture-positive sepsis and 20 had culture-positive meningitis. Diagnosed sepsis was associated with lower test scores with mean differences in reading of -0.08 SDS (95% CI: -0.10 to -0.05) and mathematics of -0.08 SDS (95% CI: -0.10 to -0.05). Diagnosed meningitis was associated with even lower test scores with mean differences in reading of -0.22 SDS (95% CI: -0.43 to 0.00) and mathematics of -0.31 SDS (95% CI: -0.55 to -0.07). These findings remained consistent even in sibling-matched analyses. Similar results were also found when only culture-positive infections were compared with the reference population. Sepsis caused by Escherichia coli showed the largest reduction in test scores, whereas group B Streptococcus appeared not to affect point estimates.

Discussion: Early-onset sepsis was associated with modest reductions in test scores. This may be insignificant for the individual but could be important on a public health level. Early-onset meningitis was associated with more substantial reductions, emphasizing the severity of this condition even in children able to attend public school.