Is air temperature at birth associated with body mass index in 9-10 year-old children?

Several studies suggest that temperature (season) at birth affects body weight and obesity years later. This study related air temperature at birth to body mass index in Liverpool primary school children (n = 11,084). No association was found between body mass index categories and month or season of birth and only weak correlations with month of birth and air temperature at birth. These correlations disappeared when controlled for precise age and an index of deprivation but girls in the third quintile for deprivation had a higher body mass index if born in colder weather.