Specific language disorders and season of birth: Underlying environmental factors or chance findings?

Abstract

The medical records of 358 children and adolescents with specific language disorders (SLD; 122 girls and 236 boys) seen in rehabilitation centers from Northern and Central Italy were examined to compare season of birth in these cases to those of the Italian population. Exposure was calculated using univariate and multivariate odds ratios (ORs) and 95% confidence intervals (CIs). Compared to the Italian population, patients with SLD had a 1.67 (95% CI [1.35–2.07]) chance of birth in October–December. Independent predictors were younger age at inclusion and being firstborn. Different neurobiological hypotheses can be drawn to explain these findings.

Keywords:

• Birth season
• Specific language disorder
• Environmental factor
• Child neurodevelopment
• Fetal brain development