Season of birth in Danish children with language disorder born in the 1958-1976 period.

Two preliminary studies have indicated a variation in season of birth in severely language-disordered children. In the current study, the season of birth in 472 Danish children with language disorder born between 1958 and 1976 was compared with the season of birth of all Danish live-born children in the same period. For some part of the period (1964-1969), an excess of boys born in November was found. Particular attention was given to the inconsistent findings also found in language-related disorders like infantile autism and dyslexia and the choice of statistical method to determine seasonality.